Oxime ester photoinitiators

ABSTRACT

Compounds of the formulae I, II, III, IV and V 
                         
wherein
         R 1  i.a. is C 4 -C 9 cycloalkanoyl, C 1 -C 12 alkanoyl, C 4 -C 6 alkenoyl, or benzoyl; R 2  is for example phenyl, C 1 -C 20 alkyl, C 3 -C 8 cycloalkyl, C 2 -C 20 alkanoyl, or benzoyl; Ar 1  is R 4 S-phenyl or NR 5 R 6 -phenyl, each of which optionally is substituted; or Ar 1  i.a. is       
                         
optionally substituted; or Ar 1  is naphthyl or anthracyl each of which is unsubstituted or substituted; or Ar 1  is benzoyl, naphthalenecarbonyl, phenanthrenecarbonyl, anthracenecarbonyl or pyrenecarbonyl, each of which is unsubstituted or substituted, or Ar 1  is 3,4,5-trimethoxyphenyl, phenoxyphenyl or biphenyl; Ar 2  i.a. is
 
                         
optionally substituted, or naphthyl or anthracyl, each of which is unsubstituted or substituted, x is 2 or 3; M 1  when x is 2, for example is phenylene, naphthalene, anthracylene, each of which optionally is substituted; M 1 , when x is 3, is a trivalent radical; M 2  for example is
 
                         
M 3  is for example C 1 -C 12 alkylene, cyclohexylene, or phenylene; n is 1-20; R 3  is for example hydrogen or C 1 -C 12 alkyl; R 3 ′ i.a. is C 1 -C 12 alkyl; substituted or —O-interrupted C 2 -C 6 alkyl; R 4  is for example hydrogen, or C 1 -C 12 alkyl; and R 5  and R 6  independently of each other i.a. are hydrogen, C 1 -C 12 alkyl, or phenyl; are suitable as photoinitiators in particular in resist applications.

This application is a divisional of U.S. application Ser. No.09/734,625, filed Dec. 12, 2000, now U.S. Pat. No. 6,949,678, whichapplication is hereby incorporated by reference.

The invention pertains to new oxime ester compounds and their use asphotoinitiators in photopolymerizable compositions.

From U.S. Pat. No. 3,558,309 it is known that certain oxime esterderivatives are photoinitiators. In U.S. Pat. No. 4,255,513 oxime estercompounds are disclosed. U.S. Pat. No. 4,202,697 disclosesacrylamino-substituted oxime esters. In JP 7-140658 A, Bull. Chem. Soc.Jpn. 1969, 42(10), 2981-3, Bull. Chem. Soc. Jpn. 1975, 48(8), 2393-4,Han'guk Somyu Konghakhoechi 1990, 27(9), 672-85, Macromolecules, 1991,24(15), 4322-7 and European Polymer Journal, 1970, 933-943 some aldoximeester compounds are described. In U.S. Pat. No. 4,590,145 and JP61-24558-A several benzophenone oxime ester compounds are disclosed. InChemical Abstract No. 96:52526c, J. Chem. Eng. Data 9(3), 403-4 (1964),J. Chin. Chem. Soc. (Taipei) 41 (5) 573-8, (1994), JP 62-273259-A(=Chemical Abstract 109:83463w), JP 62-286961-A (=Derwent No.88-025703/04), JP 62-201859-A (=Derwent No. 87-288481/41), JP62-184056-A (=Derwent No. 87-266739/38), U.S. Pat. No. 5,019,482 and J.of Photochemistry and Photobiology A 107, 261-269 (1997) somep-alkoxy-phenyl oxime ester compounds are described.

In photopolymerization technology there still exists a need for highlyreactive, easy to prepare and easy to handle photoinitiators. Inaddition, such new photoinitiators must meet the high requirements ofthe industry regarding properties like, for example, thermal stabilityand storage stability.

Surprisingly it was found, that compounds of the formulae I, II, III, IVand V

wherein

R₁ is C₄-C₉cycloalkanoyl, or C₁-C₁₂alkanoyl which is unsubstituted orsubstituted by one or more halogen, phenyl or CN; or R₁ isC₄-C₆alkenoyl, provided that the double bond is not conjugated with thecarbonyl group; or R₁ is benzoyl which is unsubstituted or substitutedby one or more C₁-C₆alkyl, halogen, CN, OR₃, SR₄ or NR₅R₆; or R¹ isC₂-C₆alkoxycarbonyl, benzyloxycarbonyl; or phenoxycarbonyl which isunsubstituted or substituted by one or more C₁-C₆alkyl or halogen;

R₂ is phenyl which is unsubstituted or substituted by one or moreC₁-C₆alkyl, phenyl, halogen, OR₃, SR₄ or NR₅R₆; or R₂ is C₁-C₂₀alkyl orC₂-C₂₀alkyl optionally interrupted by one or more —O— and/or optionallysubstituted by one or more halogen, OH, OR₃, phenyl, or phenylsubstituted by OR₃, SR₄ or NR₅R₆; or R₂ is C₃-C₈cycloalkyl,C₂-C₂₀alkanoyl; or benzoyl which is unsubstituted or substituted by oneor more C₁-C₆alkyl, phenyl, OR₃, SR₄ or NR₅R₆; or R₂ isC₂-C₁₂alkoxycarbonyl optionally interrupted by one or more —O— and/oroptionally substituted by one or more hydroxyl groups; or R₂ isphenoxycarbonyl which is unsubstituted or substituted by C₁-C₆alkyl,halogen, phenyl, OR₃, SR₄ or NR₅R₆; or R₂ is —CONR₅R₆, CN;

Ar₁ is

each of which is optionally substituted 1 to 4 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl, benzyl, OR₃, SR₄, SOR₄, SO₂R₄ or NR₅R₆,wherein the substituents OR₃, SR₄ or NR₅R₆ optionally form 5- or6-membered rings via the radicals R₃, R₄, R₅ and/or R₆ with furthersubstituents on the phenyl ring or with one of the carbon atoms of thephenyl ring;

provided that

-   -   (i) if SR₄ is 2-SC(CH₃)₃, R¹ is not benzoyl;    -   (ii) if SR₄ is 2-SCH₃ or 4-SCH₃, R₁ is not 2-iodobenzoyl or        4-methoxybenzoyl;    -   (iii) NR₅R₆ is not 4-N(CH₃)₂ or 2-NHCO-phenyl;    -   (iv) if NR₅R₆ is 2-NH₂, 2-NHCOCH₃, 4-NHCOCH₃, 2-NHCOOCH₃, R¹ is        not acetyl;    -   (v) if NR₅R₆ is 4-NHCO-phenyl, R₁ is not benzoyl; and    -   (vi) if NR₅R₆ is 4-N(CH₂CH₃)₂, R¹ is not        3,5-bis(1,1-dimethylethyl)-4-hydroxybenzoyl;

or Ar₁ is

optionally substituted 1 to 3 times by halogen, C₁-C₁₂alkyl,C₃-C₈cycloalkyl, benzyl, OR₃, SOR₄ or SO₂R₄, wherein the substituentsOR₃ and/or OR₃′ optionally form a 6-membered ring via the radicals R₃and/or R₃′ with further substituents on the phenyl ring or with one ofthe carbon atoms of the phenyl ring;

provided that

-   -   (vii) if Ar₁ is 2,4-dimethoxyphenyl, R₁ is not acetyl or        benzoyl;    -   (viii) if Ar₁ is 3,5-dibromo-2,4-dimethoxyphenyl, R₁ is not        chloroacetyl; and    -   (ix) if Ar₁ is 2,5-dimethoxyphenyl, 2-acetyloxy-3-methoxyphenyl,        2,4,5-trimethoxyphenyl, 2,6-diacetoxy-4-methylphenyl or        2,6-diacetoxy-4-acetoxymethylphenyl, R₁ is not acetyl;

or Ar₁ is

each of which is unsubstituted or substituted 1 to 9 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl; or each of which is substituted by phenylor by phenyl which is substituted by one or more OR₃, SR₄ or NR₅R₆; oreach of which is substituted by benzyl, benzoyl, C₂-C₁₂alkanoyl;C₂-C₁₂alkoxycarbonyl optionally interrupted by one or more —O— and/oroptionally substituted by one or more hydroxyl groups; or each of whichis substituted by phenoxycarbonyl, OR₃, SR₄, SOR₄, SO₂R₄ or NR₅R₆,wherein the substituents OR₃, SR₄ or NR₅R₆ optionally form 5- or6-membered rings via the radicals R₃, R₄, R₅ and/or R₆ with furthersubstituents on the fused aromatic ring or with one of the carbon atomsof the fused aromatic ring;

provided that

-   -   (x) Ar₁ is not 1-naphthyl, 2-naphthyl, 2-methoxy-1-naphthyl,        4-methoxy-1-naphthyl, 2-hydroxy-1-naphthyl,        4-hydroxy-1-naphthyl, 1,4-diacetyloxy-2-naphthyl,        1,4,5,8-tetramethoxy-2-naphthyl, 9-phenanthryl, 9-anthryl; and    -   (xi) if Ar₁ is 10-(4-chlorophenylthio)-9-anthryl, R₁ is not        pivaloyl;

or Ar₁ is benzoyl, naphthalenecarbonyl, phenanthrenecarbonyl,anthracenecarbonyl or pyrenecarbonyl, each of which is unsubstituted orsubstituted 1 to 9 times by halogen, C_(1-C) ₁₂alkyl, C₃-C₈cycloalkyl,phenyl, phenyl which is substituted by one or more OR₃, SR₄ or NR₅R₆; oreach of which is substituted by benzyl, benzoyl, C₂-C₁₂alkanoyl;C₂-C₁₂alkoxycarbonyl optionally interrupted by one or more —O— and/oroptionally substituted by one or more hydroxyl groups, phenoxycarbonyl,OR₃, SR₄, SOR₄, SO₂R₄ or NR₅R₆, wherein the substituents OR₃, SR₄ andNR₅R₆ optionally form 5- or 6-membered rings via the radicals R₃, R₄, R₅and/or R₆ with further substituents on the fused aromatic ring or withone of the carbon atoms of the fused aromatic ring;

provided that

-   -   (xii) if Ar₁ is benzoyl, R¹ is not acetyl, benzoyl nor        4-methylbenzoyl;    -   (xiii) if Ar₁ is 4-benzoyloxybenzoyl or 4-chloromethylbenzoyl,        R₁ is not benzoyl;    -   (xiv) if Ar₁ is 4-methylbenzoyl, 4-bromobenzoyl or        2,4-dimethylbenzoyl, R₁ is not acetyl;

or Ar₁ is 3,4,5-trimethoxyphenyl, or phenoxyphenyl;

or Ar₁ is biphenylyl, optionally substituted 1 to 9 times by halogen,C₁-C₁₂alkyl, C₄-C₉-cycloalkanoyl, —(CO)OR₃, —(CO)NR₅R₆, —(CO)R₈, OR₃,SR₄ and/or NR₅R₆ wherein the substituents C₁-C₁₂alkyl, —(CO)R₈, OR₃, SR₄or NR₅R₆ optionally form 5- or 6-membered rings via the radicalsC₁-C₁₂alkyl, R₃, R₄, R₅, R₈ and/or R₆ with further subsitutents on thephenyl ring or with one of the carbon atoms of the phenyl ring;

provided that

-   -   (xv) if Ar₁ is 2-biphenylyl, R₁ is not benzoyl;

or Ar₁ is

both optionally substituted 1 to 4 times by halogen, C₁-C₁₂alkyl,C₃-C₈cycloalkyl, benzyl, OR₃, SR₄ or NR₅R₆, wherein the substituentsOR₃, SR₄ or NR₅R₆ optionally form 5- or 6-membered rings via theradicals R₃, R₄, R₅ and/or R₆ with further subsitutents on the phenylring or with one of the carbon atoms of the phenyl ring or with thesubstituent R₈;

or Ar₁ is thienyl or 1-methyl-2-pyrrolyl; provided that R₁ is acetyl;

Ar₂ is

each of which is unsubstituted or substituted 1 to 9 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl, phenyl; phenyl which is substituted by oneor more OR₃, SR₄ or NR₅R₆; or each of which is substituted by benzyl,benzoyl, C₂-C₁₂alkanoyl; C₂-C₁₂alkoxycarbonyl optionally interrupted byone or more —O— and/or optionally substituted by one or more hydroxylgroups; phenoxycarbonyl, OR₃, SR₄, SOR₄, SO₂R₄ or NR₅R₆, wherein thesubstituents OR₃, SR₄ or NR₅R₆ optionally form 5- or 6-membered ringsvia the radicals R₃, R₄, R₅ and/or R₆ with further substituents on thefused aromatic ring or with one of the carbon atoms of the fusedaromatic ring;

provided that

-   -   (xvi) if Ar₂ is 1-naphthyl, 2-naphthyl or 1-hydroxy-2-naphthyl,        R₂ is not methyl, ethyl, n-propyl, butyl, phenyl or CN;    -   (xvii) if Ar₂ is 2-hydroxy-1-naphthyl, 2-acetoxy-1-naphthyl,        3-phenanthryl, 9-phenanthryl or 9-anthryl R₂ is not methyl; and    -   (xviii) if Ar₂ is 6-methoxy-2-naphthyl, R₁ is not (CH₃)₃CCO nor        4-chlorobenzoyl;

x is 2 or 3;

M₁ when x is 2,

each of which optionally is substituted 1 to 8 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl; phenyl which is unsubstituted orsubstituted by one or more OR₃, SR₄ or NR₅R₆; or each of which issubstituted by benzyl, benzoyl, C₂-C₁₂alkanoyl; C₂-C₁₂alkoxycarbonyloptionally interrupted by one or more —O— and/or optionally substitutedby one or more hydroxyl groups; or each of which is substituted byphenoxycarbonyl, OR₃, SR₄, SOR₄, SO₂R₄ or NR₅R₆;

provided that

-   -   (xix) M₁ is not 1,3-phenylene, 1,4-phenylene,        1-acetoxy-2-methoxy-4,6-phenylene or        1-methoxy-2-hydroxy-3,5-phenylene;

M₁, when x is 3, is

each of which optionally is substituted 1 to 12 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl; phenyl which is unsubstituted orsubstituted by one or more OR₃, SR₄ or NR₅R₆; or each of which issubstituted by benzyl, benzoyl, C₂-C₁₂alkanoyl; C₂-C₁₂alkoxycarbonyloptionally interrupted by one or more —O— and/or optionally substitutedby one or more hydroxyl groups; or each of which is substituted byphenoxycarbonyl, OR₃, SR₄, SOR₄, SO₂R₄ or NR₅R₆;

M₂ is

each of which optionally is substituted 1 to 8 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl; phenyl which is unsubstituted orsubstituted by one or more OR₃, SR₄ or NR₅R₆; or each of which issubstituted by benzyl, benzoyl, C₂-C₁₂alkanoyl; C₂-C₁₂alkoxycarbonyloptionally interrupted by one or more —O— and/or optionally substitutedby one or more hydroxyl groups; or each of which is substituted byphenoxycarbonyl, OR₃, SR₄, SOR₄, SO₂R₄ or NR₅R₆;

provided that

-   -   (xx) M₂ is not

M₃ is C₁-C₁₂alkylene, cyclohexylene, phenylene,—(CO)O—(C₂-C₁₂alkylene)-O(CO)—, —(CO)O—(CH₂CH₂O)_(n)—(CO)— or—(CO)—(C₂-C₁₂-alkylene)-(CO)—;

n is 1-20;

M₄ is a direct bond, —O—, —S—, —SS—, —NR₃—, —(CO)—, C₁-C₁₂alkylene,cyclohexylene, phenylene, naphthylene, C₂-C₁₂alkylenedioxy,C₂-C₁₂alkylenedisulfanyl, —(CO)O—(C₂-C₁₂alkylene)-O(CO)—,—(CO)O—(CH₂CH₂O)_(n)—(CO)— or —(CO)—(C₂-C₁₂-alkylene)-(CO)—; or M₄ isC₄-C₁₂alkylene or C₄-C₁₂alkylenedioxy, each of which is optionallyinterrupted by 1 to 5 —O—, —S— and/or —NR₃—;

M₅ is a direct bond, —CH₂—, —O—, —S—, —SS—, —NR₃— or —(CO)—;

M₆ is

M₇ is —O—, —S—, —SS— or —NR₃—; or M₇ is —(CO)—(C₂-C₁₂-alkylene)-(CO)O—,—NR₃(CO)—(C₂-C₁₂-alkylene)-(CO)NR₃— or C₂-C₁₂alkylenedioxy-, each ofwhich optionally is interrupted by 1 to 5 —O—, —S— and/or —NR₃—;

R₃ is hydrogen or C₁-C₂₀alkyl; or R₃ is C₂-C₈alkyl which is substitutedby —OH —SH —CN C₃-C₆alkenoxy, —OCH₂CH₂CN, —OCH₂CH₂(CO)O(C₁-C₄alkyl),—(CO)—C₁-C₄alkyl, —O(CO)-phenyl, —(CO)OH or —(CO)O(C₁-C₄alkyl); or R₃ isC₂-C₁₂alkyl which is interrupted by one or more —O—; or R₃ is—(CH₂CH₂O_(n+1)H, —(CH₂CH₂O)_(n)(CO)—C₁-C₈alkyl, C₁-C₈alkanoyl,C₃-C₁₂alkenyl, C₃-C₆alkenoyl, C₃-C₈cycloalkyl; or R₃ is benzoyl which isunsubstituted or substituted by one or more C₁-C₆alkyl, halogen, —OH orC₁-C₄alkoxy; or R₃ is phenyl or naphthyl each of which is unsubstitutedor substituted by halogen, —OH C₁-C₁₂alkyl, C₁-C₁₂alkoxy, or —(CO)R₇; orR₃ is phenyl-C₁-C₃alkyl, or Si(C₁-C₆alkyl)_(r)(phenyl)_(3−r);

r is 0, 1, 2or 3;

R₃′ is C₁-C₂₀alkyl; C₂-C₈alkyl which is substituted by —OH, —SH, —CN,C₃-C₆alkenoxy, —OCH₂CH₂CN, —OCH₂CH₂(CO)O(C₁-C₄alkyl), —(CO)—C₁-C₄alkyl,—(CO)-phenyl, —(CO)OH or —(CO)O(C₁-C₄alkyl); or R₃′ is C₂-C₁₂alkyl whichis interrupted by one or more —O—; or R₃′ is —(CH₂CH₂O)_(n+1)H,—(CH₂CH₂O)_(n)(CO)—C₁-C₈alkyl, C₂-C₈alkanoyl, C₃-C₁₂alkenyl,C₃-C₆alkenoyl, C₃-C₈cycloalkyl; or R₃′ is benzoyl which is unsubstitutedor substituted by one or more C₁-C₆alkyl, halogen, —OH or C₁-C₄alkoxy;or R₃′ is phenyl or naphthyl, each of which is unsubstituted orsubstituted by halogen, —OH C₁-C₁₂alkyl, C₁-C₁₂alkoxy, or —(CO)R₇; or R₃is phenyl-C₁-C₃alkyl, or Si(C₁-C₆alkyl)_(r))phenyl)_(3−r);

R₄ is hydrogen, C₁-C₂₀alkyl, C₃-C₁₂alkenyl, C₃-C₈cycloalkyl,phenyl-C₁-C₃alkyl; C₂-C₈alkyl which is substituted by —OH, —SH, —CN,C₃-C₆alkenoxy, —OCH₂CH₂CN, —OCH₂CH₂(CO)O(C₁-C₄alkyl), —(CO)—C₁-C₄alkyl,—(CO)-phenyl, —(CO)OH or —(CO)O(C₁-C₄alkyl); or R₄ is C₂-C₁₂alkyl whichis interrupted by one or more —O— or —S—; or R₄ is —(CH₂CH₂O)_(n+1)H,—(CH₂CH₂O)_(n)(CO)—C₁-C₈alkyl, C₂-C₈alkanoyl, benzoyl, C₃-C₁₂alkenyl,C₃-C₆alkenoyl; or R₄ is phenyl or naphthyl, each of which isunsubstituted or substituted by halogen, C₁-C₁₂alkyl, C₁-C₁₂alkoxy,phenyl-C₁-C₃alkyloxy, phenoxy, C₁-C₁₂alkylsulfanyl, phenylsulfanyl,—N(C₁-C₁₂alkyl)₂, diphenylamino, —(CO)R₇, —(CO)OR₇ or (CO)N(R₇)₂;

R₅ and R₆ independently of each other are hydrogen, C₁-C₂₀alkyl,C₂-C₄hydroxyalkyl, C₂-C₁oalkoxyalkyl, C₃-C₅alkenyl, C₃-C₈cycloalkyl,phenyl-C₁-C₃alkyl, C₂-C₈alkanoyl, C₃-C₁₂-alkenoyl, benzoyl; or R₅ and R₆are phenyl or naphthyl each of which is unsubstituted or substituted byC₁-C₁₂alkyl, C₁-C₁₂alkoxy or —(CO)R₇; or R₅ and R₆ together areC₂-C₆alkylene optionally interrupted by —O— or —NR₃— and/or optionallysubstituted by hydroxyl, C₁-C₄alkoxy, C₂-C₄alkanoyloxy or benzoyloxy;and

R₇ is hydrogen, C₁-C₂₀alkyl; C₂-C₈alkyl which is substituted by halogen,phenyl, —OH, —SH, —CN, C₃-C₆alkenoxy, —OCH₂CH₂CN,—OCH₂CH₂(CO)O(C₁-C₄alkyl)^(n)—O(CO)—C₁-C₄alkyl, —O(CO)-phenyl, —(CO)OHor —(CO)O(C₁-C₄alkyl); or R₇ is C₂-C₁₂alkyl which is interrupted by oneor more —O—; or R₇ is —(CH₂CH₂O)_(n+1)H, —(CH₂CH₂O)_(n)(CO)—C₁-C₈alkyl,C₃-C₁₂alkenyl, C₃-C₈cycloalkyl; or is phenyl optionally substituted byone or more halogen, —OH C₁-C₁₂alkyl, C₁-C₁₂alkoxy, phenoxy,C₁-C₁₂alkylsulfanyl, phenylsulfanyl, —N(C₁-C₁₂alkyl)₂ or diphenylamino;

R₈ is C₁-C₁₂alkyl optionally substituted by one or more halogen, phenyl,CN, —OH, —SH, C₁-C₄alkoxy, —(CO)OH or —(CO)O(C₁-C₄alkyl); or R₈ isC₃-C₆alkenyl; or phenyl optionally substituted by one or moreC₁-C₆alkyl, halogen, CN, OR₃, SR₄ or NR₅R₆; exhibit an unexpectedly goodperformance in photopolymerization reactions.

Substituted radicals phenyl are substituted one to four times, forexample one, two or three times, especially two times. Substituents onthe phenyl ring are preferably in positions 4 or in 3,4-, 3,4,5-, 2,6-,2,4- or 2,4,6-configuration on the phenyl ring.

Substituted aryl radicals Ar₁, Ar₂ are substituted 1 to 9 or 1 to 7times respectively. It is evident that a defined aryl radical cannothave more substituents than free positions at the aryl ring. Theradicals are substituted 1 to 9 times, for example 1 to 6 times or 1 to4 times, in particular one, two or three times.

C₁-C₂₀alkyl is linear or branched and is, for example, C₁-C₁₈-, C₁-C₁₄-,C₁-C₁₂-, C₁-C₈-, C₁-C₆- or C₁-C₄alkyl or C₄-C₁₂- or C₄-C₈alkyl. Examplesare methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl,tert-butyl, pentyl, hexyl, heptyl, 2,4,4-trimethylpentyl, 2-ethylhexyl,octyl, nonyl, decyl, dodecyl, tetradecyl, pentadecyl, hexadecyl,octadecyl and icosyl. C₂-C₂₀alkyl, C₁-C₁₂alkyl, C₂-C₁₂alkyl, C₁-C₆alkyl,C₂-C₆alkyl and C₁-C₄alkyl have the same meanings as given above forC₁-C₂₀alkyl up to the corresponding number of C-atoms.

C₂-C₂₀alkyl which is interrupted by one or more —O— is for exampleinterrupted 1-9, 1-5, 1-3 or once or twice by —O—. Two O-atoms areseparated by at least two methylene groups, namely ethylene. The alkylgroups are linear or branched. For example the following structuralunits will occur, —CH₂—CH₂—O—CH₂CH₃, —[CH₂CH₂O]_(y)—CH₃, wherein y=1-9,—(CH₂—CH₂O)₇—CH₂CH₃, —CH₂—CH(CH₃)—O—CH₂—CH₂CH₃ or—CH₂—CH(CH₃)—O—CH₂—CH₃. C₂-C₆alkyl which is interrupted by 1 or 2 —O— isfor example —CH₂CH₂—O—CH₂CH₂—OCH₂CH₃ or —CH₂CH₂—O—CH₂CH₃.

C₂-C₄hydroxyalkyl means C₂-C₄alkyl, which substituted by one or twoO-atoms. The alkyl radical is linear or branched. Examples are2-hydroxyethyl, 1-hydroxyethyl, 1-hydroxypropyl, 2-hydroxypropyl,3-hydroxypropyl, 1-hydroxybutyl, 4-hydroxybutyl, 2-hydroxybutyl,3-hydroxybutyl, 2,3-dihydroxypropyl, or 2,4-dihydroxybutyl.

C₃-C₈cycloalkyl is for example cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cyclooctyl, especially cyclopentyl and cyclohexyl.

C₁-C₄alkoxy is linear or branched, for example, methoxy, ethoxy,propoxy, isopropoxy, n-butyloxy, sec-butyloxy, isobutyloxy,tert-butyloxy.

C₂-C₁₀alkoxyalkyl is C₂-C₁₀alkyl, which is interrupted by one O-atom.C₂-C₁₀alkyl has the same meanings as given above for C₁-C₂₀alkyl up tothe corresponding number of C-atoms. Examples are methoxymethyl,methoxyethyl, methoxypropyl, ethoxymethyl, ethoxyethyl, ethoxypropyl,porpoxymethyl, prpopxyethyl, propoxypropyl.

C₂-C₂₀alkanoyl is linear or branched and is, for example, C₂-C₁₈-,C₂C₁₄-, C₂-C₁₂-, C₂-C₈-, C₂- C₆- or C₂-C₄alkanoyl or C₄-C₁₂- orC₄-C₈alkanoyl. Examples are acetyl, propionyl, butanoyl, isobutanoyl,pentanoyl, hexanoyl, heptanoyl, octanoyl, nonanoyl, decanoyl,dodecanoyl, tetradecanoyl, pentadecanoyl, hexadecanoyl, octadecanoyl,icosanoyl, preferably acetyl.

C₁-C₁₂alkanoyl, C₂-C₁₂alkanoyl, C₁-C₈alkanoyl, C₂-C₈alkanoyl andC₂-C₄alkanoyl have the same meanings as given above for C₂-C₂₀alkanoylup to the corresponding number of C-atoms.

C₄-C₉cycloalkanoyl is for example cyclopropanoyl, cyclobutanoyl,cyclopentanoyl, cyclohexanoyl, cyclooctanoyl.

C₂-C₄alkanoyloxy is linear or branched, for example acetyloxy,propionyloxy, butanoyloxy, isobutanoyloxy, preferably acetyloxy.

C₂-C₁₂alkoxycarbonyl is a linear or branched and is, for example,methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, n-butyloxycarbonyl,isobutyloxycarbonyl, 1,1-dimeth-ylpropoxycarbonyl, pentyloxycarbonyl,hexyloxycarbonyl, heptyloxycarbonyl, octyloxycarbonyl, nonyloxycarbonyl,decyloxycarbonyl or dodecyloxycarbonyl, especially methoxycarbonyl,ethoxycarbonyl, propoxycarbonyl, n-butyloxycarbonyl oriso-butyloxycarbonyl, preferably methoxycarbonyl.

C₂-C₆alkoxycarbonyl have the same meanings as given above forC₂-C₁₂alkoxycarbonyl up to the corresponding number of C-atoms.

C₂-C₁₂alkoxycarbonyl which is interrupted by one or more —O— is linearor branched. Two O-atoms are separated by at least two methylene groups,namely ethylene.

Phenoxycarbonyl is

Substituted phenoxycarbonyl radicals are substituted one to four times,for example one, two or three times, especially two or three times.Substituents on the phenyl ring are preferably in positions 4 or in3,4-, 3,4,5-, 2,6-, 2,4- or 2,4,6-position on the phenyl ring, inparticular in 4- or 3,4-position.

Phenyl-C₁-C₃alkyl is for example benzyl, phenylethyl, α-methylbenzyl orα,α-dimethylbenzyl, especially benzyl.

C₃-C₁₂alkenyl radicals may be mono- or polyunsaturated and are forexample allyl, methallyl, 1,1-dimethylallyl, 1-butenyl, 3-butenyl,2-butenyl, 1,3-pentadienyl, 5-hexenyl, 7-octenyl or dodecenyl,especially allyl. C₃-C₅alkenyl radicals have the same meanings as givenabove for C₃-C₁₂alkenyl radicals up to the corresponding number ofC-atoms.

C₃-C₆alkenoxy radicals may be mono- or polyunsaturated and are forexample allyloxy, methallyloxy, butenyloxy, pentenoxy,1,3-pentadienyloxy, 5-hexenyloxy.

C₃-C₆alkenoyl radicals may be mono- or polyunsaturated and are forexample propenoyl, 2-methyl-propenoyl, butenoyl, pentenoyl,1,3-pentadienoyl, 5-hexenoyl.

Halogen is fluorine, chlorine, bromine and iodine, especially fluorine,chlorine and bromine, preferably fluorine and chlorine.

Phenoxyphenyl is 2-phenoxyphenyl, 3-phenoxyphenyl or 4-phenoxyphenyl.Biphenylyl is 2-biphenylyl, 3-biphenylyl or 4-biphenylyl.

Thienyl is 1-thienyl or 2-thienyl.

If the substituents OR₃, SR₄ and NR₅R₆ on a phenyl ring form 5- or6-membered rings via the radicals R₃, R₄, R₅ and/or R₆ with furthersubstituents on the phenyl ring or with one of the carbon atoms of thephenyl ring, structures comprising two or four rings (inclusive thephenyl ring) are obtained. Examples are

If the substituents C₁-C₁₂alkyl, —(CO)R₈, OR₃, SR₄ or NR₅R₆ on abiphenylyl group form 5- or 6-membered rings via the radicalsC₁-C₁₂alkyl, R₃, R₄, R₅, R₆ and/or R₈ with further substituents on thephenyl ring or with one of the carbon atoms of the phenyl ring,structures comprising three or four rings (inclusive the biphenylylgroup) are obtained. Examples are

If the substituents OR₃, SR₄ or NR₅R₆ on a group R₈(CO)-phenyl form 5-or 6-membered rings via the radicals R₃, R₄, R₅ and/or R₆ with furthersubstituents on the phenyl ring or with one of the carbon atoms of thephenyl ringor the substituent R₈ structures comprising two or threerings (inclusive the phenyl group) are obtained. If R₈ is phenylexamples are

Preferred are compounds of the formulae I and II according to the claim1, wherein

R₁ is C₂-C₆alkoxycarbonyl or benzyloxycarbonyl; C₁-C₁₂alkanoyl which isunsubstituted or substituted by one or more halogen or phenyl; or R₁ isC₄-C₆alkenoyl, provided that the double bond is not conjugated with thecarbonyl group; or R, is benzoyl which is unsubstituted or substitutedby one or more C₁-C₆alkyl or halogen;

Ar₁ is

each of which optionally substituted 1 to 4 times by halogen,C₁-C₁₂alkyl, OR₃, SR₄ or NR₅R₆, wherein the substituents OR₃, SR₄ orNR₅R₆ optionally form 5- or 6-membered rings via the radicals R₃, R₄, R₅and/or R₆ with further substituents on the phenyl ring or with one ofthe carbon atoms of the phenyl ring;

or Ar₁ is

optionally substituted 1 to 3 times by halogen, C₁-C₁₂alkyl, OR₃,wherein the substituents OR₃ and/or OR₃′ optionally form a 6-memberedring via the radicals R₃ and/or R₃′ with further substituents on thephenyl ring or with one of the carbon atoms of the phenyl ring;

or Ar₁ is naphthyl, which is unsubstituted or substituted 1 to 7 timesby halogen, C₁-C₁₂alkyl, OR₃, SR₄ or NR₅R₆, wherein the substituentsOR₃, SR₄ or NR₅R₆ optionally form 5- or 6-membered rings via theradicals R₃, R₄, R₅ and/or R₆ with further substituents on the fusedaromatic ring or with one of the carbon atoms of the naphthyl ring;

or Ar₁ is biphenylyl, optionally substituted 1 to 9 times by halogen,C₁-C₁₂alkyl, —(CO)R₈, OR₃, SR₄ or NR₅R₆ wherein the substituentsC₁-C₁₂alkyl, OR₃, SR₄ or NR₅R₆ optionally form 5- or 6-membered ringsvia the radicals C₁-C₁₂alkyl, R₃, R₄, R₅ and/or R₆ with furthersubsitutents on the phenyl ring or with one of the carbon atoms of thephenyl ring;

or Ar₁ is

both optionally substituted 1 to 4 times by halogen, C₁-C₁₂alkyl, OR₃,SR₄, SOR₄, SO₂R₄, or NR₅R₆ wherein the substituents OR₃, SR₄ or NR₅R₆optionally form 5- or 6-membered rings via the radicals R₃, R₄, R₅and/or R₆ with further subsitutents on the phenyl ring or with one ofthe carbon atoms of the phenyl ring or with R₈;

M₁ is

each of which optionally is substituted 1 to 8 times by halogen,C₁-C₁₂alkyl, phenyl, OR₃, SR₄ or NR₅R₆.

Particularly preferred are compounds of the formula I or II, wherein

R₁ is C₁-C₁₂alkanoyl, benzoyl or C₂-C₆alkoxycarbonyl;

Ar₁ is R₄S-phenyl or NR₅R₆-phenyl, each of which is optionallysubstituted by C₁-C₈alkyl, OR₃, or SR₄; or Ar₁ is

optionally substituted by OR₃; or Ar₁ is 1-naphthyl or 2-naphthyl eachof which optionally is substituted by OR₃, SR₄ or NR₅R₆; or Ar₁ is3,4,5-trimethoxyphenyl, or phenoxyphenyl; or Ar₁ is biphenylyl,optionally substituted by C₁-C₁₂alkyl, OR₃ and/or NR₅R₆ wherein thesubstituents C₁-C₁₂alkyl, OR₃, SR₄ or NR₅R₆ optionally form 5- or6-membered rings via the radicals C₁-C₁₂alkyl, R₃, R₄, R₅, and/or R₆with further subsitutents on the phenyl ring or with one of the carbonatoms of the phenyl ring;

or Ar₁ is

both optionally substituted by OR₃ or SR₄ wherein the substituents OR₃or SR₄ optionally form 5- or 6-membered rings via the radicals R₃ and/orwith further subsitutents on the phenyl ring or with one of the carbonatoms of the phenyl ring or with the substituent R₈;

or Ar₁ is thienyl or 1-methyl-2-pyrrolyl; provided that R₁ is acetyl;

x is 2;

M₁ is

which optionally is substituted by OR₃;

M₄ is a direct bond, —O—, —S—, —SS—, or C₂-C₁₂alkylenedioxy;

R₃ is C₁-C₈alkyl, phenyl or phenyl-C₁-C₃alkyl;

R₃′ is C₁-C₈alkyl, C₃-C₁₂alkenyl or phenyl-C₁-C₃alkyl;

R₄ is C₁-C₂₀alkyl, phenyl-C₁-C₃alkyl, benzoyl; or is phenyl or naphthyl,both of which are unsubstituted or substituted by C₁-C₁₂alkyl,phenyl-C₁-C₃alkyloxy, —(CO)R₇ or —(CO)OR₇;

R₅ and R₆ independently of each other are hydrogen, phenyl-C₁-C₃alkyl,C₂-C₈alkanoyl, or phenyl;

R₇ is C₁-C₂₀alkyl or phenyl;

R₈ is phenyl optionally substituted by OR₃.

Further preferred are compounds of the formula III, IV or V, wherein

R₁ is C₂-C₆alkoxycarbonyl or benzyloxycarbonyl; C₁-C₁₂alkanoyl which isunsubstituted or substituted by one or more halogen or phenyl; or R₁ isC₄-C₆alkenoyl, provided that the double bond is not conjugated with thecarbonyl group; or R₁ is benzoyl which is unsubstituted or substitutedby one or more C₁-C₆alkyl or halogen;

R₂ is phenyl which is unsubstituted or substituted by one or moreC₁-C₆alkyl, phenyl, halogen, OR₃, SR₄ or NR₅R₆; or R₂ is C₁-C₂₀alkyl,optionally interrupted by one or more —O— and/or optionally substitutedby one or more halogen, OH, OR₃;phenyl or phenyl substituted by OR₃, SR₄or NR₅R₆;

Ar₂ is

naphthyl or naphthoyl, each of which is unsubstituted or substituted 1to 9 times by halogen, C₁-C₁₂alkyl, phenyl, OR₃, SR₄ or NR₅R₆, whereinthe substituents OR₃, SR₄ or NR₅R₆ optionally form 5- or 6-memberedrings via the radicals R₃, R₄, R₅ and/or R₆ with further substituents onthe fused aromatic ring or with one of the carbon atoms of the naphthylring;

M₂ is

each of which optionally is substituted 1 to 8 times by halogen,C₁-C₁₂alkyl, phenyl, OR₃, SR₄ or NR₅R₆; and

M₃ is C₁-C₁₂alkylene, or phenylene.

Another preferred embodiment are compounds of the formula III, wherein

R¹ is C₁-C₆alkanoyl or benzoyl;

R₂ is C₁-C₂₀alkyl or C₂-C₂₀alkyl;

Ar₂ is

naphthyl or naphthoyl, each of which is unsubstituted or substituted byOR₃, or SR₄;

R₃ and R₃′ are C₁-C₂₀alkyl; and

R₄ is phenyl.

In particular preferred compounds according to the present invention are4-phenylsulfanyl-benzaldehyde oxime-O-acetate, 2,5-diethoxy-benzaldehydeoxime-O-acetate, 2,6-dimethoxy-benzaldehyde oxime-O-acetate,2,4,6-trimethoxy-benzaldehyde oxime-O-acetate,2,3,4-trimethoxy-benzaldehyde oxime-O-acetate,3-benzylsulfanyl-benzaldehyde oxime-O-acetate,3-phenylsulfanyl-benzaldehyde oxime-O-acetate,4-methylsulfanyl-benzaldehyde oxime-O-acetate,4-(5-tert-butyl-2-methyl-phenylsulfanyl)-benzaldehyde oxime-O-acetate,4-(4-benzoyl-phenylsulfanyl)-benzaldehyde oxime-O-acetate,2-ethoxy-4-methyl-5-methylsulfanyl-benzaldehyde oxime-O-acetate,2-octyloxy-4-methyl-5-methylsulfanyl-benzaldehyde oxim-O-acetate,4-methoxy-3-phenylsulfanyl-benzaldehyde oxime-O-acetate,3-phenoxy-4-phenylsulfanyl-benzaldehyde oxime-O-acetate,3,4-bis-methylsulfanyl-benzaldehyde oxime-O-acetate,3-benzylsulfanyl-benzaldehyde oxime-O-acetate,4,8-dimethoxy-naphthalene-1-carbaldehyde oxime-O-acetate,4-phenylsulfanyl-naphthalene-1-carbaldehyde oxime-O-acetate,6-methoxy-biphenylyl-3-carbaldehyde oxime-O-acetate,4-methoxy-biphenylyl-3-carbaldehyde oxime-O-acetate,2-methoxy-5-(4-methoxybenzoyl)-benzaldehyde oxime-O-acetate,4-octyloxy-biphenylyl-3-carbaldehyde oxime-O-acetate,4-diphenylamino-benzaldehyde oxime-O-acetate,9-oxo-9.H.-thioxanthene-2-carbaldehyde oxime-O-acetate,9.H.-fluorene-2-carbaldehyde oxime-O-acetate,2,4-bis-pentyloxy-benzaldehyde oxime-O-acetate,2,4,5-trimethoxy-benzaldehyde oxime-O-acetate,4-(4-benzyloxy-phenylsulfanyl)-benzaldehyde oxime-acetate,4-(naphthalen-2-ylsulfanyl)-benzaldehyde oxime-acetate,2-Methoxy-4-methylsulfanyl-benzaldehyde oxime-acetate,Thianthrene-2-carbaldehyde oxime-acetate,2-Octyloxy-naphthalene-1-carbaldehyde oxime-acetate,5,5′-thiobis(2-benzyloxybenzaldehyde oxime-O-acetate),5,5′-thiobis(2-methoxybenzaldehyde oxime-O-acetate),4,4′-diethoxy-biphenylyl-3,3′-dicarbaldehyde dioxime-O,O′-diacetate.

Preferred compounds of formulae I and II are characterized in that theycontain at least one alkylthio or arylthio subsituent (SR₄), alkylaminoor arylamino substituent (NR₅R₆), aryl substituent, alkanoyl or aroylsubstituent, or at least two alkoxy or aryloxy substituents (OR₃, OR₃′)and simultaneously a fused aromatic ring on the aryl group linked to thecarbon atom of the oximino group

Oxime esters of formulae I, II, III, IV and V are prepared by methodsdescribed in the literature, for example by reaction of thecorresponding oximes with an acyl chloride or an anhydride in an inertsolvent such as for example t-Butyl methyl ether, tetrahydrofuran (THF)or di-methylformamide in the presence of a base, for exampletriethylamine or pyridine, or in a basic solvent such as pyridine.

Such reactions are well known to those skilled in the art, and aregenerally carried out at temperatures of −15 to +50° C., preferably 0 to25° C.

The compounds of formulae II, IV and V can be obtained analogously byusing the appropriate oximes as starting materials:

R₁, Ar₁, M₁-M₃, R₂, x and Ar₂ have the meanings as given above.

The oximes required as starting materials can be obtained by a varietyof methods described in standard chemistry textbooks (for instance in J.March, Advanced Organic Chemistry, 4th Edition, Wiley Interscience,1992), or in specialized monographs, for example, S. R. Sandier & W.Karo, Organic functional group preparations, Vol. 3, Academic Press. Oneof the most convenient methods is, for example, the reaction ofaldehydes or ketones with hydroxylamine or its salt in polar solventslike ethanol or aqueous ethanol. In that case, a base such as sodiumacetate or pyridine is added to control the pH of the reaction mixture.It is well known that the rate of the reaction is pH-dependent, and thebase can be added at the beginning or continuously during the reaction.Basic solvents such as pyridine can also be used as base and/or solventor cosolvent. The reaction temperature is generally the refluxingtemperature of the mixture, usually about 60-120° C.

Another convenient synthesis of oximes is the nitrosation of “active”methylene groups with nitrous acid or an alkyl nitrite. Both alkalineconditions, as described for example in Organic Syntheses coil. Vol. VI(J. Wiley & Sons, New York, 1988), pp 199 and 840, and acidicconditions, as described, for example, in Organic Synthesis coil. vol V,pp 32 and 373, coil. vol. III, pp 191 and 513, coll. vol.II, pp. 202,204 and 363, are suitable for the preparation of the oximes used asstarting materials in the invention. Nitrous acid is usually generatedfrom sodium nitrite. The alkyl nitrite can be for example methylnitrite, ethyl nitrite, isopropyl nitrite, butyl nitrite, or isoamylnitrite.

Every oxime ester group can exist in two configurations, (Z) or (E). Itis possible to separate the isomers by conventional methods, but it isalso possible to use the isomeric mixture as such as photoinitiatingspecies. Therefore, the invention also relates to mixtures ofconfigurational isomers of compounds of the formulae I, II, III, IV andV.

In accordance with the invention, the compounds of the formulae I, II,III, IV and V can be used as photoinitiators for the photopolymerizationof ethylenically unsaturated compounds or of mixtures which comprisesuch compounds.

Another subject of the present invention therefore is aphotopolymerizable composition comprising

(a) at least one ethylenically unsaturated photopolymerizable compoundand

(b) as photoinitiator, at least one compound of the formula I, II, III,IV and/or V

wherein

R¹ is C₄-C₉cycloalkanoyl, or C₁-C₁₂alkanoyl which is unsubstituted orsubstituted by one or more halogen, phenyl or CN; or R¹ isC₄-C₆alkenoyl, provided that the double bond is not conjugated with thecarbonyl group; or R₁ is benzoyl which is unsubstituted or substitutedby one or more C₁-C₆alkyl, halogen, CN, OR₃, SR₄ or NR₅R₆; or R₁ isC₂-C₆alkoxycarbonyl, benzyloxycarbonyl; or phenoxycarbonyl which isunsubstituted or substituted by one or more C₁-C₆alkyl or halogen;

R₂ is phenyl which is unsubstituted or substituted by one or moreC₁-C₆alkyl, phenyl, halogen, OR₃, SR₄ or NR₅R₆; or R₂ is C₁-C₂₀alkyl orC₂-C₂₀alkyl optionally interrupted by one or more —O— and/or optionallysubstituted by one or more halogen, OH, OR₃, phenyl, or phenylsubstituted by OR₃, SR₄ or NR₅R₆; or R₂ is C₃-C₈cycloalkyl,C₂-C₂₀alkanoyl; or benzoyl which is unsubstituted or substituted by oneor more C₁-C₆alkyl, phenyl, OR₃, SR₄ or NR₅R₆;

or R₂ is C₂-C₁₂alkoxycarbonyl optionally interrupted by one or more —O—and/or optionally substituted by one or more hydroxyl groups; or R₂ isphenoxycarbonyl which is unsubstituted or substituted by C₁-C₆alkyl,halogen, phenyl, OR₃, SR₄ or NR₅R₆; or R₂ is —CONR₅R₆, CN;

Ar₁ is

each of which is optionally substituted 1 to 4 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl, benzyl, OR₃, SR₄, SOR₄, SO₂R₄ or NR₅R₆,wherein the substituents OR₃, SR₄ or NR₅R₆ optionally form 5- or6-membered rings via the radicals R₃, R₄, Rs and/or R₆ with furthersubstituents on the phenyl ring or with one of the carbon atoms of thephenyl ring;

or Ar₁ is

optionally substituted 1 to 3 times by halogen, C₁-C₁₂alkyl,C₃-C₈cycloalkyl, benzyl, OR₃, SOR₄ or SO₂R₄, wherein the substituentsOR₃ and/or OR₃′ optionally form a 6-membered ring via the radicals R₃and/or R₃′ with further substituents on the phenyl ring or with one ofthe carbon atoms of the phenyl ring;

or Ar₁ is

each of which is unsubstituted or substituted 1 to 9 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl; or each of which is substituted by phenylor by phenyl which is substituted by one or more OR₃, SR₄ or NR₅R₆; oreach of which is substituted by benzyl, benzoyl, C₂-C₁₂alkanoyl;C₂-C₁₂alkoxycarbonyl optionally interrupted by one or more —O— and/oroptionally substituted by one or more hydroxyl groups; or each of whichis substituted by phenoxycarbonyl, OR₃, SR₄, SOR₄, SO₂R₄ or NR₅R₆,wherein the substituents OR₃, SR₄ or NR₅R₆ optionally form 5- or6-membered rings via the radicals R₃, R₄, R₅ and/or R₆ with furthersubstituents on the fused aromatic ring or with one of the carbon atomsof the fused aromatic ring;

or Ar₁ is benzoyl, naphthalenecarbonyl, phenanthrenecarbonyl,anthracenecarbonyl or pyrenecarbonyl, each of which is unsubstituted orsubstituted 1 to 9 times by halogen, C₁-C₁₂alkyl, C₃-C₈cycloalkyl,phenyl, phenyl which is substituted by one or more OR₃, SR₄ or NR₅R₆; oreach of which is substituted by benzyl, benzoyl, C₂-C₁₂alkanoyl;C₂-C₁₂alkoxycarbonyl optionally interrupted by one or more —O— and/oroptionally substituted by one or more hydroxyl groups, phenoxycarbonyl,OR₃, SR₄, SOR₄, SO₂R₄ or NR₅R₆, wherein the substituents OR₃, SR₄ andNR₅R₆ optionally form 5- or 6-membered rings via the radicals R₃, R₄, R₅and/or R₆ with further substituents on the fused aromatic ring or withone of the carbon atoms of the fused aromatic ring;

provided that if Ar₁ is 4-benzoyloxybenzoyl, R₁ is not benzoyl; or Ar₁is biphenylyl, optionally substituted 1 to 9 times by halogen, C₁-C₁₂alkyl, C₄-C₉-cycloalkanoyl, —(CO)OR₃, —(CO)NR₅R₆, —(CO)R₈, OR₃, SR₄and/or NR₅R₆ wherein the substituents C₁-C₁₂alkyl, —(CO)R₈, OR₃, SR₄ orNR₅R₆ optionally form 5- or 6-membered rings via the radicalsC₁-C₁₂alkyl, R₃, R₄, R₅, R₈ and/or R₆ with further subsitutents on thephenyl ring or with one of the carbon atoms of the phenyl ring;

or Ar₁ is

both optionally substituted 1 to 4 times by halogen, C₁-C₁₂alkyl,C₃-C₈cycloalkyl, benzyl, OR₃, SR₄ or NR₅R₆, wherein the substituentsOR₃, SR₄ or NR₅R₆ optionally form 5- or 6-membered rings via theradicals R₃, R₄, R₅ and/or R₆ with further subsitutents on the phenylring or with one of the carbon atoms of the phenyl ring or with thesubstituent R₈;

or Ar₁ is 3,4,5-trimethoxyphenyl, or phenoxyphenyl; or Ar₁ is thienyl or1-methyl-2-pyrrolyl; provided that R₁ is acetyl;

Ar₂ is

each of which is unsubstituted or substituted 1 to 9 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl, phenyl; phenyl which is substituted by oneor more OR₃, SR₄ or NR₅R₆; or each of which is substituted by benzyl,benzoyl, C₂-C₁₂alkanoyl; C₂-C₁₂alkoxycarbonyl optionally interrupted byone or more —O— and/or optionally substituted by one or more hydroxylgroups; phenoxycarbonyl, OR₃, SR₄, SOR₄, SO₂R₄ or NR₅R₆, wherein thesubstituents OR₃, SR₄ or NR₅R₆ optionally form 5- or 6-membered ringsvia the radicals R₃, R₄, R₅ and/or R₆ with further substituents on thefused aromatic ring or with one of the carbon atoms of the fusedaromatic ring;

provided that if Ar₂ is 1-naphthyl or 2-naphthyl, R₂ is not methyl orphenyl;

x is 2 or 3;

M₁ when x is 2, is

each of which optionally is substituted 1 to 8 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl; phenyl which is unsubstituted orsubstituted by one or more OR₃, SR₄ or NR₅R₆; or each of which issubstituted by benzyl, benzoyl, C₂-C₁₂alkanoyl; C₂-C₁₂alkoxycarbonyloptionally interrupted by one or more —O— and/or optionally substitutedby one or more hydroxyl groups; or each of which is substituted byphenoxycarbonyl, OR₃, SR₄, SOR₄, SO₂R₄ or NR₅R₆;

provided that M₁ is not 1,3-phenylene, 1,4-phenylene,1-acetoxy-2-methoxy-4,6-phenylene or 1-methoxy-2-hydroxy-3,5-phenylene;

M₁, when x is 3, is

each of which optionally is substituted 1 to 12 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl; phenyl which is unsubstituted orsubstituted by one or more OR₃, SR₄ or NR₅R₆; or each of which issubstituted by benzyl, benzoyl, C₂-C₁₂alkanoyl; C₂-C₁₂alkoxycarbonyloptionally interrupted by one or more —O— and/or optionally substitutedby one or more hydroxyl groups; or each of which is substituted byphenoxycarbonyl, OR₃, SR₄, SOR₄, SO₂R₄ or NR₅R₆;

M₂ is

each of which optionally is substituted 1 to 8 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl; phenyl which is unsubstituted orsubstituted by one or more OR₃, SR₄ or NR₅R₆; or each of which issubstituted by benzyl, benzoyl, C₂-C₁₂alkanoyl; C₂-C₁₂alkoxycarbonyloptionally interrupted by one or more —O— and/or optionally substitutedby one or more hydroxyl groups; or each of which is substituted byphenoxycarbonyl, OR₃, SR₄, SOR₄, SO₂R₄ or NR₅R₆;

M₃ is C₁-C₁₂alkylene, cyclohexylene, phenylene,—(CO)O—(C₂-C₁₂alkylene)-O(CO)—, —(CO)O—(CH₂CH₂O)_(n)—(CO)— or—(CO)—(C₂-C₁₂-alkylene)-(CO)—;

n is 1-20;

M₄ is a direct bond, —O—, —S—, —SS—, —NR₃—, —(CO)—, C₁-C₁₂alkylene,cyclohexylene, phenylene, naphthylene, C₂-C₁₂alkylenedioxy,C₂-C₁₂alkylenedisulfanyl, —(CO)O—(C₂-C₁₂alkylene)-O(CO)—,—(CO)O—(CH₂CH₂O)_(n)—(CO)— or —(CO)—(C₂-C₁₂-alkylene)-(CO)—; or M₄ isC₄-C₁₂alkylene or C₄-C₁₂alkylenedioxy, each of which is optionallyinterrupted by 1 to 5 —O—, —S— and/or —NR₃—;

M₅ is a direct bond, —CH₂—, —O—, —S—, —SS—, —NR₃— or —(CO)—;

M₆ is

M₇ is —O—, —S—, —SS— or —NR₃—; or M₇ is —(CO)—(C₂-C₁₂-alkylene)-(CO)O—,—NR₃(CO)—(C₂-C₁₂-alkylene)-(CO)NR₃— or C₂-C₁₂alkylenedioxy-, each ofwhich optionally is interrupted by 1 to 5 —O—, —S— and/or —NR₃—;

R₃ is hydrogen or C₁-C₂₀alkyl; or R₃ is C₂-C₈alkyl which is substitutedby —OH, —SH, —CN, C₃-C₆alkenoxy, —OCH₂CH₂CN, —OCH₂CH₂(CO)O(C₁-C₄alkyl),—(CO)—C₁-C₄alkyl, —O(CO)-phenyl, —(CO)OH or —(CO)O(C₁-C₄alkyl); or R₃ isC₂-C₁₂alkyl which is interrupted by one or more —O—; or R₃ is—(CH₂CH₂O)_(n+1)H, —(CH₂CH₂O)_(n)(CO)—C₁-C₈alkyl, C₁-C₈alkanoyl,C₃-C₁₂alkenyl, C₃-C₆alkenoyl, C₃-C₈cycloalkyl; or R₃ is benzoyl which isunsubstituted or substituted by one or more C₁-C₆alkyl, halogen, —OH orC₁-C₄alkoxy; or R₃ is phenyl or naphthyl each of which is unsubstitutedor substituted by halogen, —OH C₁-C₁₂alkyl, C₁-C₁₂alkoxy, or —(CO)R₇; orR₃ is phenyl-C₁-C₃alkyl, or Si(C₁-C₆alkyl)_(r)(phenyl)_(3−r);

r is 0, 1, 2 or 3;

R₃′ is C₁-C₂₀alkyl; C₂-C₈alkyl which is substituted by —OH, —SH, —CN,C₃-C₆alkenoxy, —OCH₂CH₂CN, —OCH₂CH₂(CO)O(C₁-C₄alkyl), —(CO)—C₁-C₄alkyl,—(CO)-phenyl, —(CO)OH or —(CO)O(C₁-C₄alkyl); or R₃′ is C₂-C₁₂alkyl whichis interrupted by one or more —O—; or R₃′ is —(CH₂CH₂O)_(n+1)H,—(CH₂CH₂O)_(n)(CO)—C₁-C₈alkyl, C₂-C₈alkanoyl, C₃-C₁₂alkenyl,C₃-C₆alkenoyl, C₃-C₈cycloalkyl; or R₃′ is benzoyl which is unsubstitutedor substituted by one or more C₁-C₆alkyl,halogen, —OH or C₁-C₄alkoxy; orR₃′ is phenyl or naphthyl, each of which is unsubstituted or substitutedby halogen, —OH, C₁-C₁₂alkyl, C₁-C₁₂alkoxy, or —(CO)R₇; or R₃ isphenyl-C₁-C₃alkyl, or Si(C₁-C₆alkyl)_(r))phenyl)_(3−r);

R₄ is hydrogen, C₁-C₂₀alkyl, C₃-C₁₂alkenyl, C₃-C₈cycloalkyl,phenyl-C₁-C₃alkyl; C₂-C₈alkyl which is substituted by —OH, —SH, —CN,C₃-C₆alkenoxy, —OCH₂CH₂CN, —OCH₂CH₂(CO)O(C₁-C₄alkyl), —(CO)—C₁-C₄alkyl,—(CO)-phenyl, —(CO)OH or —(CO)O(C₁-C₄alkyl); or R₄ is C₂-C₁₂alkyl whichis interrupted by one or more —O— or —S—; or R₄ is —(CH₂CH₂O)_(n+1)H,—(CH₂CH₂O)_(r))CO)—C₁-C₈alkyl, C₂-C₈alkanoyl, benzoyl, C₃-C₁₂alkenyl,C₃-C₆alkenoyl; or R₄ is phenyl or naphthyl, each of which isunsubstituted or substituted by halogen, C₁-C₁₂alkyl, C₁-C₁₂alkoxy,phenyl-C₁-C₃alkyloxy, phenoxy, C₁-C₁₂alkylsulfanyl, phenylsulfanyl,—N(C₁-C₁₂alkyl)₂, diphenylamino, —(CO)R₇, —(CO)OR₇ or (CO)N(R₇)₂; R₅ andR₆ independently of each other are hydrogen, C₁-C₂₀alkyl,C₂-C₄hydroxyalkyl, C₂-C₁₀alkoxyalkyl, C₃-C₅alkenyl, C₃-C₈cycloalkyl,phenyl-C₁-C₃alkyl, C₂-C₈alkanoyl, C₃-C₁₂-alkenoyl, benzoyl; or R₅ and R₆are phenyl or naphthyl each of which is unsubstituted or substituted byC₁-C₁₂alkyl, C₁-C₁₂alkoxy or —(CO)R₇; or R₅ and R₆ together areC₂-C₆alkylene optionally interrupted by —O— or —NR₃— and/or optionallysubstituted by hydroxyl, C₁-C₄alkoxy, C₂-C₄alkanoyloxy or benzoyloxy;and

R₇ is hydrogen, C₁-C₂₀alkyl; C₂-C₈alkyl which is substituted by halogen,phenyl, —OH, —SH, —CN, C₃-C₆alkenoxy, —OCH₂CH₂CN,—OCH₂CH₂(CO)O(C₁-C₄alkyl), —(CO)—C₁-C₄alkyl, —O(CO)-phenyl, —(CO)OH or—(CO)O(C₁-C₄alkyl); or R₇ is C₂-C₁₂alkyl which is interrupted by one ormore —O—; or R₇ is —(CH₂CH₂O)_(n+1)H, —(CH₂CH₂O)_(n)(CO)—C₁-C₈alkyl,C₃-C₁₂alkenyl, C₃-C₈cycloalky or is phenyl optionally substituted by oneor more halogen, —OH, C₁-C₁₂alkyl, C₁-C₁₂alkoxy, phenoxy,C₁-C₁₂alkylsulfanyl, phenylsulfanyl, —N(C₁-C₁₂alkyl)₂ or diphenylamino;R₈ is C₁-C₁₂alkyl optionally substituted by one or more halogen, phenyl,CN, —OH, —SH, C₁-C₄alkoxy, —(CO)OH or —(CO)O(C₁-C₄alkyl); or R₈ isC₃-C₆alkenyl; or phenyl optionally substituted by one or moreC₁-C₆alkyl, halogen, CN, OR₃, SR₄ or NR₅R₆.

The composition may comprise additionally to the photoinitiator (b) atleast one further photoinitiator (c), and/or other additives (d).

The unsaturated compounds (a) may include one or more olefinic doublebonds. They may be of low (monomeric) or high (oligomeric) molecularmass. Examples of monomers containing a double bond are alkyl,hydroxyalkyl or amino acrylates, or alkyl, hydroxyalkyl or aminomethacrylates, for example methyl, ethyl, butyl, 2-ethylhexyl or2-hydroxyethyl acrylate, isobornyl acrylate, methyl methacrylate orethyl methacrylate. Silicone acrylates are also advantageous. Otherexamples are acrylonitrile, acrylamide, methacrylamide, N-substituted(meth)acrylamides, vinyl esters such as vinyl acetate, vinyl ethers suchas isobutyl vinyl ether, styrene, alkyl- and halostyrenes,N-vinylpyrrolidone, vinyl chloride or vinylidene chloride.

Examples of monomers containing two or more double bonds are thediacrylates of ethylene glycol, propylene glycol, neopentyl glycol,hexamethylene glycol or of bisphenol A, and4,4′-bis(2-acryl-oyloxyethoxy)diphenylpropane, trimethylolpropanetriacrylate, pentaerythritol triacrylate or tetraacrylate, vinylacrylate, divinylbenzene, divinyl succinate, diallyl phthalate, triallylphosphate, triallyl isocyanurate or tris(2-acryloylethyl)isocyanurate.

Examples of polyunsaturated compounds of relatively high molecular mass(oligomers) are acrylated epoxy resins, polyesters containing acrylate-,vinyl ether- or epoxy-groups, and also polyurethanes and polyethers.Further examples of unsaturated oligomers are unsaturated polyesterresins, which are usually prepared from maleic acid, phthalic acid andone or more diols and have molecular weights of from about 500 to 3000.In addition it is also possible to employ vinyl ether monomers andoligomers, and also maleate-terminated oligomers with polyester,polyurethane, polyether, polyvinyl ether and epoxy main chains. Ofparticular suitability are combinations of oligomers which carry vinylether groups and of polymers as described in WO 90/01512. However,copolymers of vinyl ether and maleic acid-functionalized monomers arealso suitable. Unsaturated oligomers of this kind can also be referredto as prepolymers.

Particularly suitable examples are esters of ethylenically unsaturatedcarboxylic acids and polyols or polyepoxides, and polymers havingethylenically unsaturated groups in the chain or in side groups, forexample unsaturated polyesters, polyamides and polyurethanes andcopolymers thereof, polymers and copolymers containing (meth)acrylicgroups in side chains, and also mixtures of one or more such polymers.

Examples of unsaturated carboxylic acids are acrylic acid, methacrylicacid, crotonic acid, itaconic acid, cinnamic acid, and unsaturated fattyacids such as linolenic acid or oleic acid. Acrylic and methacrylic acidare preferred.

Suitable polyols are aromatic and, in particular, aliphatic andcycloaliphatic polyols. Examples of aromatic polyols are hydroquinone,4,4′-dihydroxydiphenyl, 2,2-di(4-hydroxyphenyl)propane, and alsonovolaks and resols. Examples of polyepoxides are those based on theabovementioned polyols, especially the aromatic polyols, andepichlorohydrin. Other suitable polyols are polymers and copolymerscontaining hydroxyl groups in the polymer chain or in side groups,examples being polyvinyl alcohol and copolymers thereof orpolyhydroxyalkyl methacrylates or copolymers thereof. Further polyolswhich are suitable are oligoesters having hydroxyl end groups.

Examples of aliphatic and cycloaliphatic polyols are alkylenediolshaving preferably 2 to 12 C atoms, such as ethylene glycol, 1,2- or1,3-propanediol, 1,2-, 1,3- or 1,4-butanediol, pentanediol, hexanediol,octanediol, dodecanediol, diethylene glycol, triethylene glcyol,polyethylene glycols having molecular weights of preferably from 200 to1500, 1,3-cyclopentanediol, 1,2-, 1,3- or 1,4-cyclohexanediol,1,4-dihydroxymethylcyclohexane, glycerol, tris(β-hydroxyethyl)amine,trimethylolethane, trimethylolpropane, pentaerythritol,dipentaerythritol and sorbitol.

The polyols may be partially or completely esterified with onecarboxylic acid or with different unsaturated carboxylic acids, and inpartial esters the free hydroxyl groups may be modified, for exampleetherified or esterified with other carboxylic acids.

Examples of Esters are:

trimethylolpropane triacrylate, trimethylolethane triacrylate,trimethylolpropane trimeth-acrylate, trimethylolethane trimethacrylate,tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate,tetraethylene glycol diacrylate, pentaerythritol diacrylate,pentaerythritol triacrylate, pentaerythritol tetraacrylate,dipentaerythritol diacrylate, dipentaerythritol triacrylate,dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate,dipentaerythritol hexaacrylate, tripentaerythritol octaacrylate,pentaerythritol dimethacrylate, pentaerythritol trimethacrylate,dipentaerythritol dimethacrylate, dipentaerythritol tetramethacrylate,tripen-taerythritol octamethacrylate, pentaerythritol diitaconate,dipentaerythritol tris-itaconate, dipentaerythritol pentaitaconate,dipentaerythritol hexaitaconate, ethylene glycol diacrylate,1,3-butanediol diacrylate, 1,3-butanediol dimethacrylate, 1,4-butanedioldiitaconate, sorbitol triacrylate, sorbitol tetraacrylate,pentaerythritol-modified triacrylate, sorbitol tetra methacrylate,sorbitol pentaacrylate, sorbitol hexaacrylate, oligoester acrylates andmethacrylates, glycerol diacrylate and triacrylate, 1,4-cyclohexanediacrylate, bisacrylates and bismethacrylates of polyethylene glycolwith a molecular weight of from 200 to 1500, or mixtures thereof.

Also suitable as components (a) are the amides of identical ordifferent, unsaturated carboxylic acids with aromatic, cycloaliphaticand aliphatic polyamines having preferably 2 to 6, especially 2 to 4,amino groups. Examples of such polyamines are ethylenediamine, 1,2- or1,3-propylenediamine, 1,2-, 1,3- or 1,4-butylenediamine,1,5-pentylenediamine, 1,6-hexylenediamine, octylenediamine,dodecylenediamine, 1,4-diaminocyclohexane, isophoronediamine,phenylenediamine, bisphenylenediamine, di-β-aminoethyl ether,diethylenetriamine, triethylenetetramine, di(β-aminoethoxy)- ordi(β-aminopropoxy)ethane. Other suitable polyamines are polymers andcopolymers, preferably with additional amino groups in the side chain,and oligoamides having amino end groups. Examples of such unsaturatedamides are methylenebisacrylamide, 1,6-hexamethylenebisacrylamide,diethylenetriaminetrismethacrylamide, bis(methacrylamidopropoxy)ethane,β-methacrylamidoethyl methacrylate andN[(β-hydroxy-ethoxy)ethyl]acrylamide.

Suitable unsaturated polyesters and polyamides are derived, for example,from maleic acid and from diols or diamines. Some of the maleic acid canbe replaced by other dicarboxylic acids. They can be used together withethylenically unsaturated comonomers, for example styrene. Thepolyesters and polyamides may also be derived from dicarboxylic acidsand from ethylenically unsaturated diols or diamines, especially fromthose with relatively long chains of, for example 6 to 20 C atoms.Examples of polyurethanes are those composed of saturated or unsaturateddiisocyanates and of unsaturated or, respectively, saturated diols.

Polymers with (meth)acrylate groups in the side chain are likewiseknown. They may, for example, be reaction products of epoxy resins basedon novolaks with (meth)acrylic acid, or may be homo- or copolymers ofvinyl alcohol or hydroxyalkyl derivatives thereof which are esterifiedwith (meth)acrylic acid, or may be homo- and copolymers of(meth)acrylates which are esterified with hydroxyalkyl (meth)acrylates.

Other suitable polymers with acrylate or methacrylate groups in the sidechains are, for example, solvent soluble or alkaline soluble polyimideprecursors, for example poly(amic acid ester) compounds, having thephotopolymerizable side groups either attached to the backbone or to theester groups in the molecule, i.e. according to EP 624826. Sucholigomers or polymers can be formulated with the new photoinitiators andoptionally reactive diluents, like polyfunctional (meth)acrylates inorder to prepare highly sensitive polyimide precursor resists.

The photopolymerizable compounds can be used alone or in any desiredmixtures. It is preferred to use mixtures of polyol (meth)acrylates.

Examples of the component (a) are also polymers or oligomers having atleast two ethylenically unsaturated groups and at least one carboxylfunction within the molecule structure, such as a resin obtained by thereaction of a saturated or unsaturated polybasic acid anhydride with aproduct of the reaction of an epoxy compound and an unsaturatedmonocarboxylic acid (for example, EB9696, UCB Chemicals; KAYARADTCR1025, Nippon Kayaku Co.,LTD.), or an addition product formed betweena carboxyl group-containing resin and an unsaturated compound having anα,β-unsaturated double bond and an epoxy group (for example, ACA200M,Daicel Industries, Ltd.).

As diluent, a mono- or multi-functional ethylenically unsaturatedcompound, or mixtures of several of said compounds, can be included inthe above composition up to 70% by weight based on the solid portion ofthe composition.

The unsaturated compounds (a) can also be used as a mixture withnon-photopolymerizable, film-forming components. These may, for example,be physically drying polymers or solutions thereof in organic solvents,for instance nitrocellulose or cellulose acetobutyrate. They may also,however, be chemically and/or thermally curable (heat-curable) resins,examples being polyisocyanates, polyepoxides and melamine resins, aswell as polyimide precursors. The use of heat-curable resins at the sametime is important for use in systems known as hybrid systems, which in afirst stage are photopolymerized and in a second stage are crosslinkedby means of thermal aftertreatment.

The invention also provides compositions comprising as component (a) atleast one ethylenically unsaturated photopolymerizable compound which isemulsified or dissolved in water. Many variants of suchradiation-curable aqueous prepolymer dispersions are commerciallyavailable. A prepolymer dispersion is understood as being a dispersionof water and at least one prepolymer dispersed therein. Theconcentration of water in these systems is, for example, from 5 to 80%by weight, in particular from 30 to 60% by weight. The concentration ofthe radiation-curable prepolymer or prepolymer mixture is, for example,from 95 to 20% by weight, in particular from 70 to 40% by weight. Inthese compositions the sum of the percentages given for water andprepolymer is in each case 100, with auxiliaries and additives beingadded in varying quantities depending on the intended use.

The radiation-curable, film-forming prepolymers which are dispersed inwater and are often also dissolved are aqueous prepolymer dispersions ofmono- or polyfunctional, ethylenically unsaturated prepolymers which areknown per se, can be initiated by free radicals and have for example acontent of from 0.01 to 1.0 mol of polymerizable double bonds per 100 gof prepolymer and an average molecular weight of, for example, at least400, in particular from 500 to 10,000. Prepolymers with higher molecularweights, however, may also be considered depending on the intendedapplication. Use is made, for example, of polyesters containingpolymerizable C—C double bonds and having an acid number of not morethan 10, of polyethers containing polymerizable C—C double bonds, ofhydroxyl-containing reaction products of a polyepoxide, containing atleast two epoxide groups per molecule, with at least oneα,β-ethylenically unsaturated carboxylic acid, of polyurethane(meth)acrylates and of acrylic copolymers which containα,β3-ethylenically unsaturated acrylic radicals, as are described in EP12339. Mixtures of these prepolymers can likewise be used. Also suitableare the polymerizable prepolymers described in EP 33896, which arethioether adducts of polymerizable prepolymers having an averagemolecular weight of at least 600, a carboxyl group content of from 0.2to 15% and a content of from 0.01 to 0.8 mol of polymerizable C—C doublebonds per 100 g of prepolymer. Other suitable aqueous dispersions, basedon specific alkyl (meth)acrylate polymers, are described in EP 41125,and suitable waterdispersible, radiation-curable prepolymers of urethaneacrylates can be found in DE 2936039.

Further additives which may be included in these radiation-curableaqueous prepolymer dispersions are dispersion auxiliaries, emulsifiers,antioxidants, e.g. 2,2-thiobis(4-methyl-6-t-butylphenol) or2,6-di-t-butylphenol, light stabilizers, dyes, pigments, fillers, suchas glass or alumina, for example talc, gypsum, silicic acid, rutile,carbon black, zinc oxide, iron oxides, reaction accelerators, levellingagents, lubricants, wetting agents, thickeners, flatting agents,antifoams and other auxiliaries customary in paint technology. Suitabledispersion auxiliaries are water-soluble organic compounds which are ofhigh molecular mass and contain polar groups, examples being polyvinylalcohols, polyvinylpyrrolidone or cellulose ethers. Emulsifiers whichcan be used are nonionic emulsifiers and, if desired, ionic emulsifiersas well.

In certain cases it may be of advantage to use mixtures of two or moreof the novel photoinitiators. It is of course also possible to usemixtures with known photoinitiators (c), for example mixtures withcamphor quinone, benzophenone, benzophenone derivatives, acetophenone,acetophenone derivatives, for example a-hydroxycycloalkyl phenyl ketonesor 2-hydroxy-2-methyl-1-phenyl-propanone, dialkoxyacetophenones,a-hydroxy- or a-aminoacetophenones, e.g.(4-methylthiobenzoyl)-1-methyl-i-morpholinoethane,(4-morpholinobenzoyl)-1-benzyl-1-dimethylaminopropane,4-aroyl-1,3-dioxolanes, benzoin alkyl ethers and benzil ketals, e.g.dimethyl benzil ketal, phenylglyoxalic esters and derivatives thereof,dimeric phenylglyoxalic esters, diacetyl, peresters, e.g. benzophenonetetracarboxylic peresters as described for example in EP 126541,monoacyl phosphine oxides, e.g.(2,4,6-trimethylbenzoyl)diphenylphosphine oxide, bisacylphosphineoxides, bis(2,6-dimethoxy-benzoyl)-(2,4,4-trimethyl-pentyl)-phosphineoxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide,bis(2,4,6-trimethylbenzoyl)-2,4-dipentoxyphenylphosphine oxide,trisacylphosphine oxides, halomethyltriazines, e.g.2-[2-(4-methoxy-phenyl)-vinyl]-4,6-bis-trichloromethyl-[1,3,5]triazine,2-(4-methoxy-phenyl)-4,6-bis-trichloromethyl-[1,3,5]triazine,2-(3,4-dimethoxy-phenyl)-4,6-bis-trichloromethyl-[1,3,5]triazine,2-methyl-4,6-bis-trichloromethyl-[1,3,5]triazine,2-(4-N,N-di(ethoxycarbonylmethyl)aminophenyl)-4,6-bis(trichloromethyl)-[1,3,5]triazine,2-(4-methoxy-naphthyl)-4,6-bis-trichloromethyl-[1,3,5]triazine,2-(1,3-benzodioxol-5-yl)-4,6-bis-trichloromethyl-[1,3,5]triazine,2-[2-[4-(pentyloxy)phenyl]ethenyl]-4,6-bis-trichloromethyl-[1,3,5]triazine,2-[2-(3-methyl-2-furanyl)-ethenyl]-4,6-bis-trichloromethyl-[1,3,5]triazine,2-[2-(5-methyl-2-furanyl)-ethenyl]-4,6-bis-trichloromethyl-[1,3,5]triazine,2-[2-(2,4-dimethoxy-phenyl)-ethenyl]-4,6-bis-trichloromethyl-[1,3,5]triazine,2-[2-(2-methoxy-phenyl)ethenyl]-4,6-bis-trichloromethyl-[1,3,5]-triazine,2-[2-[4-isopropyloxy-phenyl]-ethenyl]-4,6-bis-trichloromethyl-[1,3,5]triazine,2-[2-(3-chloro-4-methoxy-phenyl)ethenyl]-4,6-bis-trichloromethyl-[1,3,5]triazine,2-[2-bromo-4-N,N-di(ethoxycarbonylmethyl)amino-phenyl]-4,6-bis-trichloromethyl-[1,3,5]triazine,2-[2-chloro-4-N,N-di(ethoxycarbonylmethyl)amino-phenyl]-4,6-bis-trichloromethyl-[1,3,5]triazine,2-[3-bromo-4-N,N-di(ethoxycarbonylmethyl)amino-phenyl]-4,6-bis-trichloromethyl-[1,3,5]triazine,2-[3-chloro-4-N,N-di(ethoxycarbonylmethyl)amino-phenyl]-4,6-bis-trichloromethyl-[1,3,5]triazine, or other halomethyl-triazines as described for example inG.Buhr, R. Dammel and C. Lindley Polym. Mater. Sci. Eng. 61,269 (1989),and EP 0262788; halomethyl-oxazol photoinitiators, such as described inU.S. Pat. No. 4,371,606 and U.S. Pat. No. 4,371,607; 1,2-disulfones,such as described in E. A. Bartmann, Synthesis 5, 490 (1993);hexaarylbisimidazole, and hexaarylbisimidazole/coinitiators systems,e.g. ortho-chlorohexaphenyl-bisimidazole combined with2-mercaptobenzthiazole, ferrocenium compounds, or titanocenes, e.g.bis(cyclopentadienyl)-bis(2,6-difluoro-3-pyrryl-phenyl)titanium.

Where the novel photoinitiator systems are employed in hybrid systems,use is made, in addition to the novel free-radical hardeners, ofcationic photoinitiators, of peroxide compounds, such as benzoylperoxide (other suitable peroxides are described in U.S. Pat. No.4,950,581 column 19, lines 17-25), of aromatic sulfonium-, phosphonium-or iodonium salts as described for example in U.S. Pat. No. Pat.4,950,581, column 18, line 60 to column 19, line 10 orcyclopentadienyl-arene-iron(II) complex salts, for example(η⁶-iso-propylbenzene)(η⁵-cyclopentadienyl)-iron(II)hexafluorophosphate, as well as oxime sulfonic acid esters, as are, forexample described in EP 780729. Also pyridinium and (iso)quinoliniumsalts as described e.g. in EP 497531 and EP 441232 may be used incombination with the new photoinitiators. The new photoinitiators,either alone or in mixtures with other known photoinitiators andsensitizers, can be used also in the form of a dispersion or emulsion inwater or aqueous solutions.

Subject of the invention are compositions comprising besides thecompound of formula I, II, III, IV or V at least one a-aminoketone, inparticular (4-methylthiobenzoyl)-1-methyl-1-morpholinoethane.

The photopolymerizable compositions generally comprise 0.05 to 25% byweight, preferably 0.01 to 10% by weight, in particular 0.01 to 5% byweight of the photoinitiator, based on the solid composition. The amountrefers to the sum of all photoinitiators added, if mixtures ofinitiators are employed. Accordingly, the amount either refers to thephotoinitiator (b) or the photoinitiators (b)+(c).

In addition to the photoinitiator the photopolymerizable mixtures mayinclude various additives (d). Examples of these are thermal inhibitors,which are intended to prevent premature polymerization, examples beinghydroquinone, hydroquinone derivatives, p-methoxyphenol, β-naphthol orsterically hindered phenols, such as 2,6-di-tert-butyl-p-cresol In orderto increase the stability on storage in the dark it is possible, forexample, to use copper compounds, such as copper naphthenate, stearateor octoate, phosphorus compounds, for example triphenylphosphine,tributylphosphine, triethyl phosphite, triphenyl phosphite or tribenzylphosphite, quaternary ammonium compounds, for exampletetramethylammonium chloride or trimethylbenzylammonium chloride, orhydroxylamine derivatives, for example N-diethylhydroxylamine. Toexclude atmospheric oxygen during the polymerization it is possible toadd paraffin or similar wax-like substances which, being of inadequatesolubility in the polymer, migrate to the surface in the beginning ofpolymerization and form a transparent surface layer which prevents theingress of air. It is also possible to apply an oxygen-impermeable layeron top of the coating, for example poly(vinylalcohol-co-vinylacetate).Light stabilizers which can be added in a small quantity are UVabsorbers, for example those of the hydroxyphenylbenzotriazole,hydroxyphenyl-benzophenone, oxalamide or hydroxyphenyl-s-triazine type.These compounds can be used individually or in mixtures, with or withoutsterically hindered amines (HALS).

Examples of such UV absorbers and light stabilizers are

-   1. 2-(2′-hydroxphenyl)benzotriazoles for example    2-(2′-hydroxy-5′-methylphenyl)benzotriazole,    2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)benzotriazole,    2-(5′-tert-butyl-2′-hydro-xyphenyl)benzotriazole,    2-(2′-hydroxy-5′-(1,1,3,3-tetramethylbutyl)phenyl)benzotriazole,    2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)-5-chlorobenzotriazole,    2-(3′-tert-butyl-2′-hydroxy-5′-methylphenyl)-5-chlorobenzotriazole,    2-(3′-sec-butyl-5′-tert-butyl-2′-hydroxyphenyl)benzotrizole,    2-(2′-hydroxy-4′-octoxyphenyl)benzotriazole,    2-(3′,5′-di-tert-amyl-2′-hydroxyphenyl)benzotriazole,    2-(3′,5′-bis-(α,α-dimethylbenzyl)-2′-hydroxyphenyl)-benzotriazole,    mixture of    2-(3′-tert-butyl-2′-hydroxy-5′-(2-octyloxycarbonylethyl)phenyl)-5-chlorobenzotriazole,    2-(3′-tert-butyl-5′-[2-(2-ethyl-hexyl-oxy)carbonylethyl]-2′-hydroxyphenyl)-5-chlorobenzotriazole,    2-(3′-tert-butyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)phenyl)-5-chlorobenzotriazole,    2-(3′-tert-butyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)    phenyl)-benzotriazole,    2-(3′-tert-butyl-2′-hydroxy-5′-(2-octyloxycarbonylethyl)phenyl)benzotriazole,    2-(3′-tert-butyl-5′-[2-(2-ethylhexyloxy)carbonylethyl]-2′-hydroxyphenyl)benzotriazole,    2-(3′-dodecyl-2′-hydroxy-5′-methylphenyl)benzotriazole, and    2-(3′-tert-butyl-2′-hydroxy-5′-(2-isooctyloxycarbonylethyl)phenylbenzotriazole,    2,2′-methylene-bis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazol-2-yl-phenol];    transesterification product of    2-[3′-tert-butyl-5′-(2-methoxycarbonylethyl)-2′-hydroxy-phenyl]-benzotriazole    with polyethylene glycol 300; [R-CH₂CH₂—COO(CH₂)₃]₂— where    R=3′-tert-butyl-4′-hydroxy-5′-2H-benzotriazol-2-yl-phenyl.-   2. 2-Hydroxybenzoohenones, for example the 4-hydroxy-, 4-methoxy-,    4-octoxy-, 4-decyloxy-, 4-dodecyloxy-, 4-benzyloxy-,    4,2′,4′-trihydroxy- and 2′-hydroxy-4,4′-dimethoxy derivative.-   3. Esters of substituted or unsubstituted benzoicacids, for example    4-tert-butylphenyl salicylate, phenyl salicylate, octylphenyl    salicylate, dibenzoylresorcinol, bis(4-tert-butylbenzoyl)resorcinol,    benzoylresorcinol, 2,4-di-tert-butylphenyl    3,5-di-tert-butyl-4-hydroxybenzoate, hexadecyl    3,5-di-tert-butyl-4-hydroxybenzoate, octadecyl    3,5-di-tert-butyl-4-hydroxybenzoate, and    2-methyl-4,6-di-tert-butylphenyl    3,5-di-tert-butyl-4-hydroxybenzoate.-   4. Acrylates, for example isooctyl or ethyl α-cyano-β,β-diphenyl    acrylate, methyl α-carbomethoxycinnamate, butyl or methyl    α-cyano-1-methyl-p-methoxycinnamate, methyl    α-carboxymethoxy-p-methoxycinnamate and    N-(β-carbomethoxy-β-cyanovinyl)-2-methylindoline.-   5. Sterically hindered amines, for example    bis-(2,2,6,6-tetramethylpiperidyl)sebacate,    bis-(2,2,6,6-tetramethylpiperidyl)succinate,    bis-(1,2,2,6,6-pentamethylpiperidyl)sebacate,    bis-(1,2,2,6,6-pentamethylpiperidyl)n-butyl-3,5-di-tert-butyl-4-hydroxybenzylmalonate,    condensation product of    1-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic    acid, condensation product of    N,N′-bis-(2,2,6,6-tetramethyl-4-piperidyl)hexa-methylenediamine and    4-tert-octylamino-2,6-dichloro-1,3,5-s-triazine,    tris-(2,2,6,6-tetramethyl-4-piperidyl)nitrilotriacetate,    tetrakis-(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butane tetraoate,    1,1′-(1,2-ethandiyl)bis(3,3,5,5-tetramethyl-piperazinone),    4-benzoyl-2,2,6,6-tetramethylpiperidine,    4-stearyloxy-2,2,6,6-tetramethylpiperidine,    bis-(1,2,2,6,6-pentamethylpiperidyl)2-n-butyl-2-(2-hydroxy-3,5-di-tert-butylbenzyl)malonate,    3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro-[4.5]decane-2,4-dione,    bis-(1-octyloxy-2,2,6,6-tetramethylpiperidyl) sebacate,    bis-(1-octyloxy-2,2,6,6-tetramethylpiperidyl)succinate, condensation    product of    N,N′-bis-(2,2,6,6-tetra-methyl-4-piperidyl)hexamethylenediamine and    4-morpholino-2,6-dichloro-1,3,5-triazine, condensation product of    2-chloro-4,6-di-(4-n-butylamino-2,2,6,6-tetramethylpiperidyl)-1,3,5-triazine    and 1,2-bis-(3-aminopropyl-amino)ethane, condensation product of    2-chloro-4,6-di-(4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triazine    and 1,2-bis-(3-aminopropylamino)ethane,    8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione,    3-do-decyl-1-(2,2,6,6-tetramethyl-4-piperidyl)pyrrolidine-2,5-dione    and    3-dodecyl-1-(1,2,2,6,6-penta-methyl-4-piperidyl)-pyrrolidine-2,5-dione.-   6. Oxalamides, for example 4,4′-dioctyloxyoxanilide,    2,2′-diethoxyoxanilide, 2,2′-dioctyloxy-5,5′-di-tert-butyloxanilide,    2,2′-didodecyloxy-5,5′di-tert-butyloxanilide,    2-ethoxy-2′-ethyl-oxanilide,    N,N′-bis-(3-dimethylaminopropyl)oxalamide,    2-ethoxy-5-tert-butyl-2′-ethyloxanilide and its mixture with    2-ethoxy-2′-ethyl-5,4′-di-tert-butyloxanilide, mixtures of o- and    p-methoxy- and of o- and p-ethoxy-disubstituted oxanilides.-   7. 2-(2-Hydroxyphenyl)-1,3,5-triazines, for example    2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine,    2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis-(2,4-dimethylphenyl)-1,3,5-triazine,    2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,    2,4-bis(2-hydroxy-4-propyloxy-phenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazine,    2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(4-methylphenyl)-1,3,5-triazine,    2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,    2-[2-hydroxy-4-(2-hydroxy-3-butyloxy-propyloxy)phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,    2-[2-hydroxy-4-(2-hydroxy-3-octyloxy-propyloxy)phenyl]-4,6-bis(2,4-di-methylphenyl)-1,3,5-triazine,    2-[4-dodecyl/tridecyl-oxy-(2-hydroxypropyl)oxy-2-hydroxy-phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine.-   8. Phosphites and phosphonites, for example triphenyl phosphite,    diphenyl alkyl phosphites, phenyl dialkyl phosphites,    tris(nonylphenyl)phosphite, trilauryl phosphite, trioctadecyl    phosphite, distearyl pentaerythrityl diphosphite,    tris-(2,4-di-tert-butylphenyl) phosphite, diisodecyl pentaerythrityl    diphosphite, bis-(2,4-di-tert-butylphenyl)pentaerythrityl    diphosphite, bis-(2,6-di-tert-butyl-4-methylphenyl) pentaerythrityl    diphosphite, bis-isodecyloxy pentaerythrityl diphosphite,    bis-(2,4-di-tert-butyl-6-methylphenyl)pentaerythrityl diphosphite,    bis-(2,4,6-tri-tert-butylphenyl)pentaerythrityl diphosphite,    tristearyl sorbityl triphosphite,    tetrakis-(2,4-di-tert-butylphenyl)-4,4′-biphenylene diphosphonite,    6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-di-benzo[d,g]-1,3,2-dioxaphosphocine,    6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyl-dibenzo[d,g]-1,3,2-dioxaphosphocine,    bis-(2,4-di-tert-butyl-6-methylphenyl)methyl phosphite and    bis(2,4-di-tert-butyl-6-methylphenyl)ethyl phosphite.

To accelerate the photopolymerization it is possible to add amines ascomponent (d), for example triethanolamine, N-methyldiethanolamine,ethyl-p-dimethylaminobenzoate, 2-(dimethylamino)ethyl benzoate,2-ethylhexyl-p-dimethylaminobenzoate,octyl-para-N,N-dimethylaminobenzoate,N-(2-hydroxyethyl)-N-methyl-para-toluidine or Michler's ketone. Theaction of the amines can be intensified by the addition of aromaticketones of the benzophenone type. Examples of amines which can be usedas oxygen scavengers are substituted N,N-dialkylanilines, as aredescribed in EP 339841. Other accelerators, coinitiators andautoxidizers are thiols, thioethers, disulfides, phosphonium salts,phosphine oxides or phosphines, as described, for example, in EP 438123,in GB 2180358 and in JP Kokai Hei 6-68309. It is further possible to addchain transfer agents which are customary in the art to the compositionsaccording to the invention as component (d). Examples are mercaptans,amines and benzothiazol.

Photopolymerization can also be accelerated by adding furtherphotosensitizers or coinitiators (as component (d)) which shift orbroaden the spectral sensitivity. These are, in particular, aromaticcompounds, for example benzophenone and derivatives thereof,thioxanthone and derivatives thereof, anthraquinone and derivativesthereof, coumarin and phenothiazine and derivatives thereof, and also3-(aroylmethylene)thiazolines, rhodanine, camphorquinone, but alsoeosine, rhodamine, erythrosine, xanthene, thioxanthene, acridine, e.g.9-phenylacridine, 1,7-bis(9-acridinyl)heptane,1,5-bis(9-acridinyl)pentane, cyanine and merocyanine dyes.

Specific examples of such compounds are

1. Thioxanthones

Thioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone,1-chloro-4-propoxythioxanthone, 2-dodecylthioxanthone,2,4-diethylthioxanthone, 2,4-dimethylthioxanthone,1-methoxy-carbonylthioxanthone, 2-ethoxycarbonylthioxanthone,3-(2-methoxyethoxycarbonyl)-thioxanthone, 4-butoxycarbonylthioxanthone,3-butoxycarbonyl-7-methylthioxanthone, 1-cyano-3-chlorothioxanthone,1-ethoxycarbonyl-3-chlorothioxanthone,1-ethoxycarbonyl-3-ethoxythioxanthone,1-ethoxycarbonyl-3-aminothioxanthone,1-ethoxycarbonyl-3-phenylsulfurylthioxanthone,3,4-di-[2-(2-methoxyethoxy)ethoxycarbonyl]-thioxanthone,1,3-dimethyl-2-hydroxy-9H-thioxanthen-9-one 2-ethylhexylether,1-ethoxycarbonyl-3-(1-methyl-1-morpholinoethyl)-thioxanthone,2-methyl-6-dimethoxymethyl-thioxanthone,2-methyl-6-(1,1-dimethoxybenzyl)-thioxanthone,2-morpholinomethylthioxanthone, 2-methyl-6-morpholinomethylthioxanthone,N-allylthioxanthone-3,4-dicarboximide,N-octylthioxanthone-3,4-dicarboximide,N-(1,1,3,3-tetra-methylbutyl)-thioxanthone-3,4-dicarboximide,1-phenoxythioxanthone, 6-ethoxycarbonyl-2-methoxythioxanthone,6-ethoxycarbonyl-2-methylthioxanthone, thioxanthone-2-carboxylic acidpolyethyleneglycol ester,2-hydroxy-3-(3,4-dimethyl-9-oxo-9H-thioxanthon-2-yloxy)-N,N,N-trimethyl-1-propanaminiumchloride;

2. Benzophenones

benzophenone, 4-phenyl benzophenone, 4-methoxy benzophenone,4,4′-dimethoxy benzophenone, 4,4′-dimethyl benzophenone,4,4′-dichlorobenzophenone 4,4′-bis(dimethylamino)-benzophenone,4,4′-bis(diethylamino)benzophenone,4,4′-bis(methylethylamino)benzophenone,4,4′-bis(p-isopropylphenoxy)benzophenone, 4-methyl benzophenone,2,4,6-trimethyl-benzophenone, 4-(4-methylthiophenyl)-benzophenone,3,3′-dimethyl-4-methoxy benzophenone, methyl-2-benzoylbenzoate,4-(2-hydroxyethylthio)-benzophenone, 4-(4-tolylthio)-benzophenone,1-[4-(4-benzoyl-phenylsulfanyl)-phenyl]-2-methyl-2-(toluene-4-sulfonyl)-propan-1-one,4-benzoyl-N,N,N-trimethylbenzenemethanaminium chloride,2-hydroxy-3-(4-benzoylphenoxy)-N,N,N-trimethyl-1-propanaminium chloridemonohydrate, 4-(13-acryloyl-1,4,7,10,13-pentaoxatridecyl)-benzophenone,4-benzoyl-N,N-dimethyl-N-[2-(1-oxo-2-propenyl)oxy]ethyl-benzenemethanaminiumchloride;

3. Coumarins

Coumarin 1, Coumarin 2, Coumarin 6, Coumarin 7, Coumarin 30, Coumarin102, Coumarin 106, Coumarin 138, Coumarin 152, Coumarin 153, Coumarin307, Coumarin 314, Coumarin 314T, Coumarin 334, Coumarin 337, Coumarin500, 3-benzoyl coumarin, 3-benzoyl-7-methoxycoumarin,3-benzoyl-5,7-dimethoxycoumarin, 3-benzoyl-5,7-dipropoxycoumarin,3-benzoyl-6,8-dichlorocoumarin, 3-benzoyl-6-chloro-coumarin,3,3′-carbonyl-bis[5,7-di(propoxy)-coumarin],3,3′-carbonyl-bis(7-methoxycoumarin),3,3′-carbonyl-bis(7-diethylamino-coumarin), 3-isobutyroylcoumarin,3-benzoyl-5,7-dimethoxy-coumarin, 3-benzoyl-5,7-diethoxy-coumarin,3-benzoyl-5,7-dibutoxycoumarin,3-benzoyl-5,7-di(methoxyethoxy)-coumarin,3-benzoyl-5,7-di(allyloxy)coumarin, 3-benzoyl-7-dimethylaminocoumarin,3-benzoyl-7-diethylaminocoumarin, 3-isobutyroyl-7-dimethylaminocoumarin,5,7-dimethoxy-3-(1-naphthoyl)-coumarin,5,7-diethoxy-3-(1-naphthoyl)-coumarin, 3-benzoylbenzo[f]coumarin,7-diethylamino-3-thienoylcoumarin,3-(4-cyanobenzoyl)-5,7-dimethoxycoumarin,3-(4-cyanobenzoyl)-5,7-dipropoxycoumarin,7-dimethylamino-3-phenylcoumarin, 7-diethylamino-3-phenylcoumarin, thecoumarin derivatives disclosed in JP 09-179299-A and JP 09-325209-A, forexample7-[{4-chloro-6-(diethylamino)-S-triazine-2-yl}amino]-3-phenylcoumarin;

4. 3-(aroylmethylene)-thiazolines

3-methyl-2-benzoylmethylene-β-naphthothiazoline,3-methyl-2-benzoylmethylene-benzothiazoline,3-ethyl-2-propionylmethylene-β-naphthothiazoline;

5. Rhodanines

4-dimethylaminobenzalrhodanine, 4-diethylaminobenzalrhodanine,3-ethyl-5-(3-octyl-2-benzothiazolinylidene)-rhodanine, the rhodaninederivatives, formulae [1], [2], [7], disclosed in JP 08-305019A;

6. Other Compounds

acetophenone, 3-methoxyacetophenone, 4-phenylacetophenone, benzil,4,4′-bis(dimethylamino)benzil, 2-acetylnaphthalene, 2-naphthaldehyde,dansyl acid derivatives, 9,10-anthraquinone, anthracene, pyrene,aminopyrene, perylene, phenanthrene, phenanthrenequinone, 9-fluorenone,dibenzosuberone, curcumin, xanthone, thiomichler's ketone,(α(4-dimethylaminobenzylidene)ketones, e.g.2,5-bis(4-diethylaminobenzylidene)cyclopentanone,2-(4-di-methylamino-benzylidene)-indan-1-one,3-(4-dimethylamino-phenyl)-1-indan-5-yl-propenone,3-phenylthiophthalimide, N-methyl-3,5-di(ethylthio)-phthalimide,N-methyl-3,5-di(ethylthio)-phthalimide, phenothiazine,methylphenothiazine, amines, e.g. N-phenylglycine, ethyl4-di-methylaminobenzoate, butoxyethyl 4-dimethylaminobenzoate,4-dimethylaminoacetophenone, triethanolamine, methyidiethanolamine,dimethylaminoethanol, 2-(dimethylamino)ethyl benzoate,poly(propylenegylcol)-4-(dimethylamino)benzoate.

A photopolymerizable composition, comprising as further additive (d) aphotosensitizer compound selected from the group consisting ofbenzophenone and its derivatives, thioxanthone and its derivatives,anthraquinone and its derivatives, or coumarin derivatives is preferred.

The curing process can be assisted by adding photosensitizers, inparticular, in compositions which are pigmented (for example withtitanium dioxide), and also by adding a component which under thermalconditions forms free radicals, for example an azo compound such as2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile), a triazene, diazosulfide, pentazadiene or a peroxy compound, for instance a hydroperoxideor peroxycarbonate, for example t-butyl hydroperoxide, as described forexample in EP 245639.

The compositions according to the invention may comprise as furtheradditive (d) a photoreducable dye, e.g., xanthene-, benzoxanthene-,benzothioxanthene, thiazine-, pyronine-, porphyrine- or acridine dyes,and/or trihalogenmethyl compounds which can be cleaved by irradiation.Similar compositions are for example described in EP 445624.

Further additives known in the art may be added as component (d), as forexample flow improvers, adhesion promoters, such asvinyltrimethoxysilane, vinyltriethoxysilanevinyltris(2-methoxyethoxy)silane,N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane,N-(2-amino-ethyl)3aminopropyltrimethoxysilane,3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane,3-glycidoxypropylmethyidimethoxysilane,2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane,3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane,3-methacryloxypropyltrimethoxysilane and3-mercaptopropyltrimethoxysilane. Surfactants, optical brighteners,pigments, dyes, wetting agents, levelling assistants, dispersants,aggregation preventers, antioxidants or fillers are further examples foradditives (d).

In order to cure thick and pigmented coatings it is appropriate to addglass microspheres or pulverized glass fibres, as described for examplein U.S. Pat. No. 5,013,768.

The choice of additive(s) (d) is made depending on the field ofapplication and on properties required for this field. The additivesdescribed above are customary in the art and accordingly are added inamounts which are usual in the respective application.

Binders (e) as well can be added to the novel compositions. This isparticularly expedient when the photopolymerizable compounds are liquidor viscous substances. The quantity of binder may, for example, be2-98%, preferably 5-95% and especially 20-90%, by weight relative to theoverall solids content. The choice of binder is made depending on thefield of application and on properties required for this field, such asthe capacity for development in aqueous and organic solvent systems,adhesion to substrates and sensitivity to oxygen.

Examples of suitable binders are polymers having a molecular weight ofabout 2,000 to 2,000,000, preferably 5,000 to 1,000,000. Examples ofalkali developable binders are acrylic polymer having carboxylic acidfunction as a pendant group, such as conventionally known copolymersobtained by copolymerizing an ethylenic unsaturated carboxylic acid suchas (meth)acrylic acid, 2-carboxyethyl (meth)acrylic acid,2-carboxypropyl (meth)acrylic acid itaconic acid, crotonic acid, maleicacid and fumaric acid, with one or more monomers selected from esters of(meth)acrylic acid, such as methyl (meth)acrylate, ethyl (meth)acrylate,propyl (meth)acrylate, butyl (meth)acrylate, benzyl (meth)acrylate,2-ethylhexyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl(meth)acrylate; vinyl aromatic compounds, such as styrene,α-methylstyrene, vinyltoluene, p-chlorostyrene; amide type unsaturatedcompounds, (meth)acrylamide diacetone acrylamide, N-methylolacrylamide,N-butoxymethacrylamide; and polyolefin type compounds, such asbutadiene, isoprene, chloroprene and the like; methacrylonitrile, methylisopropenyl ketone, vinyl acetate, vinyl propionate, or vinyl pivalate.Examples of copolymers are copolymers of acrylates and methacrylateswith acrylic acid or methacrylic acid and with styrene or substitutedstyrene, phenolic resins, for example novolak, (poly)hydroxystyrene, andcopolymers of hydroxystyrene with alkyl acrylates, acrylic acid and/ormethacrylic acid. Preferable examples of copolymers are copolymers ofmethyl methacrylate/methacrylic acid, copolymers of benzylmethacrylate/methacrylic acid, copolymers of methyl methacrylate/ethylacrylate/methacrylic acid, copolymers of benzyl methacrylate/methacrylicacid/styrene, copolymers of benzyl methacrylate/methacrylicacid/hydroxyethyl methacrylate, copolymers of methyl methacrylate/butylmethacrylate/methacrylic acid/styrene, copolymers of methylmethacrylate/benzyl methacrylate/methacrylic acid/hydroxyphenylmethacrylate. Examples of solvent developable binder polymers arepoly(alkyl methacrylates), poly(alkyl acrylates),poly(benzylmethacrylate-co-hydroxyethylmethacrylate-co-methacrylicacid), poly(benzylmethacrylate-co-methacrylic acid); cellulose estersand cellulose ethers, such as cellulose acetate, celluloseacetobutyrate, methylcellulose, ethylcellulose; polyvinylbutyral,polyvinylformal, cyclized rubber, polyethers such as polyethylene oxide,polypropylene oxide and polytetrahydrofuran; polystyrene, polycarbonate,polyurethane, chlorinated polyolefins, polyvinyl chloride, vinylchloride/vinylidene copolymers, copolymers of vinylidene chloride withacrylonitrile, methyl methacrylate and vinyl acetate, polyvinyl acetate,copoly(ethylene/vinyl acetate), polymers such as polycaprolactam andpoly(hexamethylene adipamide), and polyesters such as poly(ethyleneglycol terephtalate) and poly(hexamethylene glycol succinate) andpolyimide binder resins.

The polyimide binder resin in the present invention can either be asolvent soluble polyimide or a polyimide precursor, for example, apoly(amic acid).

Preferred is a photopolymerizable composition, comprising as binderpolymer (e), a copolymer of methacrylate and methacrylic acid.

Interesting further are polymeric binder components as described e.g. inJP 10-171119-A, in particular for use in color filters.

The photopolymerizable compositions can be used for various purposes,for example as printing ink, e.g. screen printing inks, inks for offset-or flexo printing, as a clear finish, as a white or colored finish, forexample for wood or metal, as powder coating, as a coating material,inter alia for paper, wood, metal or plastic, as a daylight-curablecoating for the marking of buildings and roadmarking, for photographicreproduction techniques, for holographic recording materials, for imagerecording techniques or to produce printing plates which can bedeveloped with organic solvents or with aqueous alkalis, for producingmasks for screen printing, as dental filling compositions, as adhesives,as pressure-sensitive adhesives, as laminating resins, as etch resists,solder resists, electroplating resists, or permanent resists, bothliquid and dry films, as photostructurable dielectric and as soldermasks for printed circuit boards and electronic circuits, as resists tomanufacture color filters for a variety of display applications or togenerate structures in the manufacturing process of plasma-displaypanels and electroluminescence displays, (as for example described inU.S. Pat. No. 5,853,446, EP 863534, JP 09-244230-A, JP 10-62980-A, JP08-171863-A, U.S. Pat. No. 5,840,465, EP 855731, JP 05-271576-A, JP05-67405-A) for the production of optical switches, optical lattices(interference lattice), light circuits, for producing three-dimensionalarticles by mass curing (UV curing in transparent moulds) or by thestereolithography technique, as is described, for example, in U.S. Pat.No. 4,575,330, to produce composite materials (for example styrenicpolyesters, which may, if desired, contain glass fibres and/or otherfibres and other auxiliaries) and other thick-layered compositions, forcoating or sealing electronic components and integrated circuits, or ascoatings for optical fibres, or for producing optical lenses, e.g.contact lenses or Fresnel lenses. The compositions according to theinvention are further suitable for the production of medical equipment,auxiliaries or implants. Further, the compositions according to theinvention are suitable for the preparation of gels with thermotropicproperties, as for example described in DE 19700064 and EP 678534.

The novel photoinitiators may additionally be employed as initiators foremulsion polymerizations, pearl polymerizations or suspensionpolymerizations, as polymerization initiators for fixing ordered statesof liquid-crystalline monomers and oligomers, or as initiators forfixing dyes on organic materials.

In coating materials, use is frequently made of mixtures of a prepolymerwith polyunsaturated monomers, which may additionally include amonounsaturated monomer as well. It is the prepolymer here whichprimarily dictates the properties of the coating film, and by varying itthe skilled worker is able to influence the properties of the curedfilm. The polyunsaturated monomer functions as a crosslinking agentwhich renders the film insoluble. The monounsaturated monomer functionsas a reactive diluent, which is used to reduce the viscosity without theneed to employ a solvent.

Unsaturated polyester resins are usually used in two-component systemstogether with a monounsaturated monomer, preferably with styrene. Forphotoresists, specific one-component systems are often used, for examplepolymaleimides, polychalcones or polyimides, as described in DE 2308830.

The novel photoinitiators and mixtures thereof can also be used for thepolymerization of radiation-curable powder coatings. The powder coatingscan be based on solid resins and monomers containing reactive doublebonds, for example maleates, vinyl ethers, acrylates, acrylamides andmixtures thereof. A free-radically UV-curable powder coating can beformulated by mixing unsaturated polyester resins with solid acrylamides(for example methyl methylacrylamidoglycolate) and a novel free-radicalphotoinitiator, such formulations being as described, for example, inthe paper “Radiation Curing of Powder Coating”, Conference Proceedings,Radtech Europe 1993 by M. Wittig and Th. Gohmann. The powder coatingscan also contain binders, as are described, for example, in DE 4228514and in EP 636669. Free-radically UV-curable powder coatings can also beformulated by mixing unsaturated polyester resins with solid acrylates,methacrylates or vinyl ethers and with a novel photoinitiator (orphotoinitiator mixture). The powder coatings may also comprise bindersas are described, for example, in DE 4228514 and in EP 636669. TheUV-curable powder coatings may additionally comprise white or colouredpigments. For example, preferably rutiletitanium dioxide can be employedin concentrations of up to 50% by weight in order to give a cured powdercoating of good hiding power. The procedure normally compriseselectrostatic or tribostatic spraying of the powder onto the substrate,for example metal or wood, melting of the powder by heating, and, aftera smooth film has formed, radiation-curing of the coating withultraviolet and/or visible light, using for example medium-pressuremercury lamps, metal halide lamps or xenon lamps. A particular advantageof the radiation-curable powder coatings over their heat-curablecounterparts is that the flow time after melting the powder particlescan be delayed in order to ensure the formation of a smooth, high-glosscoating. In contrast to heat-curable systems, radiation-curable powdercoatings can be formulated to melt at lower temperatures without theunwanted effect of shortening their lifetime. For this reason, they arealso suitable as coatings for heat-sensitive substrates, for examplewood or plastics. In addition to the novel photoinitiator systems, thepowder coating formulations may also include UV absorbers. Appropriateexamples are listed above in sections 1.-8.

The novel photocurable compositions are suitable, for example, ascoating materials for substrates of all kinds, for example wood,textiles, paper, ceramics, glass, plastics such as polyesters,polyethylene terephthalate, polyolefins or cellulose acetate, especiallyin the form of films, and also metals such as Al, Cu, Ni, Fe, Zn, Mg orCo and GaAs, Si or SiO₂ to which it is intended to apply a protectivelayer or, by means of imagewise exposure, to generate an image.

The novel radiation-sensitive compositions further find application asnegative resists, having a very high sensitivity to light and being ableto be developed in an aqueous alkaline medium without swelling. They aresuitable as photoresists for electronics like electroplating resist,etch resist, both liquid and dry films, solder resist, as resists tomanufacture color filters for a variety of display applications or togenerate structures in the manufacturing process of plasma-displaypanels and electroluminescence displays, the production of printingplates, such as offset printing plates or screen printing plates, forthe production of printing forms for relief printing, planographicprinting, photogravure or of screen printing forms, for the productionof relief copies, for example for the production of texts in braille,for the production of stamps, for use in chemical milling or as amicroresist in the production of integrated circuits. The compositionsfurther may be used as photopatternable dielectric layer or coating,encapsulating material and isolating coating in the production ofcomputer chips, printed boards and other electric or electroniccomponents. The possible layer supports, and the processing conditionsof the coating substrates, are just as varied.

The novel composition also relates to a photosensitive thermosettingresin composition and a method of forming a solder resist pattern by theuse thereof, and more particularly relates to a novel photosensitivethermosetting resin composition useful as materials for the productionof printed circuit boards, the precision fabrication of metallicarticles, the etching of glass and stone articles, the relief of plasticarticles, and the preparation of printing plates and particularly usefulas a solder resist for printed circuit boards and to a method of forminga solder resist pattern by the steps of exposing a layer of the resincomposition selectively to an actinic ray through a photomask having apattern and developing the unexposed part of the layer.

The solder resist is a substance which is used during the soldering of agiven part to a printed circuit board for the purpose of preventingmolten solder from adhering to irrelevant portions and protectingcircuits. It is, therefore, required to possess such properties as highadhesion, insulation resistance, resistance to soldering temperature,resistance to solvents, resistance to alkalis, resistance to acids, andresistance to plating.

Because the photocurable compositions according to the invention have agood thermal stability and are sufficiently resistant to inhibition byoxygen, they are particularly suitable for the production of colorfilters or color mosaic systems, such as described, for example, in EP320 264. Color filters usually are employed in the manufacturing of LCDdisplays, projection systems and image sensors. The color filters can beused, for example, for display and image scanner in televisionreceivers, video monitors or computers, in flat panel display technologyetc.

The color filters usually are prepared by forming red, green and bluepixels and a black matrix on a glass substrate. In these processesphotocurable compositions according to the invention can be employed. Aparticularly preferred method of use comprises adding of the coloringmatters, dyes and pigments of red, green and blue colors to thelight-sensitive resin composition of the present invention, coating ofthe substrate with the composition, drying of the coating with a shortheat treatment, pattemwise exposure of the coating to actinic radiationand subsequent development of the pattern in an aqueous alkalinedeveloper solution and optionally a heat treatment. Thus, bysubsequently applying a red, green and blue pigmented coating, in anydesired order, on top of each other with this process a color filterlayer with red, green and blue color pixels can be produced.

The development is carried out by washing out the areas which were notpolymerized with a suitable alkali developing solution. This process isrepeated to form the image having plural colors.

In the light-sensitive resin composition of the present invention, witha process in which at least one or more picture elements are formed on atransparent substrate and then an exposure is given from a side of thetransparent substrate, on which the above picture elements are notformed, the above picture elements can be utilized as a light-shieldingmask. In this case, for example, in the case where an overall exposureis given, a position adjustment of a mask gets unnecessary and a concernon a position slippage thereof is removed. And, it is possible to cureall of the part on which the above picture elements are not formed.Further, in this case, it is possible as well to develop and remove apart of the portion on which the above picture elements are not formedby using partially a light-shielding mask.

Since in either case, no gap is formed between the picture elementswhich are formed formerly and those which are formed later, thecomposition of the present invention is suitable for, for example, aforming material for a color filter. To be concrete, the coloringmatters, dyes and pigments of red, green and blue colors are added tothe light-sensitive resin composition of the present invention, and theprocesses for forming an image are repeated to form the picture elementsof red, green and blue colors. Then, the light-sensitive resincomposition to which, for example, the black coloring materials, dyesand pigments are added is provided on an overall face. An overallexposure (or a partial exposure via a light-shielding mask) can beprovided thereon to form the picture elements of a black color all overthe spaces (or all but a partial region of the light-shielding mask)between the picture elements of red, green and blue colors.

In addition to a process in which the light-sensitive resin compositionis coated on a substrate and dried, the light-sensitive resincomposition of the present invention can be used as well for a layertransfer material. That is, the light-sensitive resin composition islayer-wise provided directly on a temporary support, preferably on apolyethylene terephthalate film, or on a polyethylene terephthalate filmon which an oxygen-shielding layer and a peeling layer or the peelinglayer and the oxygen-shielding layer are provided. Usually, a removablecover sheet made of a synthetic resin is laminated thereon for aprotection in handling. Further, there can be applied as well a layerstructure in which an alkali soluble thermoplastic resin layer and anintermediate layer are provided on a temporary support and further alight-sensitive resin composition layer is provided thereon (JP5-173320-A).

The above cover sheet is removed in use and the light-sensitive resincomposition layer is laminated on a permanent support. Subsequently,peeling is carried out between those layer and a temporary support whenan oxygen-shielding layer and a peeling layer are provided, between thepeeling layer and the oxygen-shielding layer when the peeling layer andthe oxygen-shielding layer are provided, and between the temporarysupport and the light-sensitive resin composition layer when either thepeeling layer or the oxygen-shielding layer is not provided, and thetemporary support is removed.

A metal support, glass, ceramics, and a synthetic resin film can be usedas a support for a color filter. Glass and a synthetic resin film whichis transparent and have an excellent dimension stability is particularlypreferred.

The thickness of the light-sensitive resin composition layer is usually0.1 to 50 micrometers, in particular 0.5 to 5 micrometers.

A diluted aqueous solution of an alkaline substance can be used used asa developing solution for the light-sensitive resin composition of thepresent invention if the composition contains alkali soluble resin oralkali soluble monomers or oligomers, and further a developer solutionprepared by adding a small amount of a water-miscible organic solventthereto is included as well.

Examples of suitable alkaline materials include alkali metal hydroxides(for example, sodium hydroxide and potassium hydroxide), alkali metalcarbonates (for example, sodium carbonate and potassium carbonate),alkali metal bicarbonates (for example, sodium bicarbonate and potassiumbicarbonate), alkali metal silicates (for example, sodium silicate andpotassium silicate), alkali metal metasilicates (for example, sodiummetasilicate and potassium metasilicate), triethanolamine,diethanolamine, monoethanolamine, morpholine, tetraalkylammoniumhydroxides (for example, tetramethylammonium hydroxide), or trisodiumphosphate. The concetration of the alkaline substance is 0.01 to 30weight %, and pH is preferably 8 to 14.

Suitable organic solvents which are miscible with water includemethanol, ethanol, 2-propanol, 1-propanol, butanol, diacetone alcohol,ethylene glycol monomethyl ether, ethylene glycol monoethyl ether,ethylene glycol mono-n-butyl ether, diethyleneglycol dimethyl ether,propyleneglycol monomethyl ether acetate, ethyl-3-ethoxypropionate,methyl-3-methoxypropionate, n-butyl acetate, benzyl alcohol, acetone,methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone,2-pentanone, epsilon-caprolactone, gamma-butylolactone,dimethylformamide, dimethylacetoamide, hexamethylphosphoramide, ethyllactate, methyl lactate, epsilon-caprolactam, andN-methyl-pyrrolidinone. The concentration of the organic solvent whichis miscible with water is 0.1 to 30 weight %.

Further, a publicly known surface active agent can be added. Theconcentration of the surface active agent is preferably 0.001 to 10weight %.

The light sensitive resin composition of the present invention can alsobe developed with organic solvents, including blends of two or moresolvents, not containing alkaline compounds. Suitable solvents includemethanol, ethanol, 2-propanol, 1-propanol, butanol, diacetone alcohol,ethylene glycol monomethyl ether, ethylene glycol monoethyl ether,ethylene glycol mono-n-butyl ether, diethyleneglycol dimethyl ether,propyleneglycol monomethyl ether acetate, ethyl-3-ethoxypropionate,methyl-3-methoxypropionate, n-butyl acetate, benzyl alcohol, acetone,methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone,2-pentanone, epsilon-caprolactone, gamma-butylolactone,dimethylformamide, dimethylacetamide, hexamethylphosphoramide, ethyllactate, methyl lactate, epsilon-caprolactam, andN-methyl-pyrrolidinone. Optionally, water can be added to these solventsup to a level at which still a clear solution is obtained and at whichsufficient solubility of the unexposed areas of the light sensitivecomposition is maintained.

The developer solution can be used in all forms known to the personskilled in the art, for example in form of a bath solution, puddle, or aspraying solution. In order to remove the noncured portion of thelight-sensitive resin composition layer, there can be combined themethods such as rubbing with a rotary brush and rubbing with a wetsponge. Usually, the temperature of the developing solution ispreferably at and around room temperature to 40° C. The developing timeis changeable according to the specific kind of the light-sensitiveresin composition, the alkalinity and temperature of the developingsolution, and the kind and concentration of the organic solvent in thecase where it is added. Usually, it is 10 seconds to 2 minutes. It ispossible to put a rinsing step after the development processing.

A final heat treatment is preferably carried out after the developmentprocessing. Accordingly, a support having a layer which isphotopolymerized by exposing (hereinafter referred to as a photocuredlayer) is heated in an electric furnace and a drier, or the photocuredlayer is irradiated with an infrared lamp or heated on a hot plate. Theheating temperature and time depend on the composition used and thethickness of the formed layer. In general, heating is preferably appliedat about 120° C. to about 250° C., for about 5 to about 60 minutes.

The pigment which can be comprised in the composition according to thepresent invention, including a pigmented color filter resistcomposition, is preferably a processed pigment, for example a powdery orpasty product prepared by finely dispersing a pigment into at least oneresin selected from the group consisting of acrylic resin, vinylchloride-vinyl acetate copolymer, maleic acid resin and ethyl celluloseresin.

The red pigment comprises, for example, an anthraquinone type pigmentalone, a perylene type pigment alone, or a mixture consisting of atleast one of them and a disazo type yellow pigment or an isoindolinetype yellow pigment, in particular C. I. Pigment Red 177 alone, C. I.Pigment Red 155 alone or a mixture consisting to at least one member ofC. I. Pigment Red 177, C. I. Pigment Red 155 and C. I. Pigment Yellow 83or C. I. Pigment Yellow 139 (“C. I.” refers to the Color Index, known tothe person skilled in the art and publicly available). Further suitableexamples for the pigment are C. I. Pigment Red 105, 144, 149, 176, 177,185, 202, 209, 214, 222, 242, 254, 255, 264, 272 and C. I. PigmentYellow 24, 31, 53, 83, 93, 95, 109, 110, 128, 129, 138, 139, 166 and C.I. Pigment Orange 43.

The green pigment comprises for instance a halogenated phthalocyaninetype pigment alone or its mixture with a disazo type yellow pigment oran isoindoline type yellow pigment, in particular C. I. Pigment Green 7alone, C. I. Pigment Green 36 alone, C. I. Pigment Green 37 alone or amixture consisting of at least one member of C. I. Pigment Green 7, C.I. Pigment Green 36, C. I. Pigment Green 37, C. I. Pigment Green 136 andC. I. Pigment Yellow 83 or C. I. Pigment Yellow 139. Other suitablegreen pigments are C. I. Pigment Green 15 and 25.

Examples for suitable blue pigments are phthalocyanine type pigments,used either alone or in combination with an dioxazine type violetpigment, for instance, a combination of C. I. Pigment Blue 15:3 and C.I. Pigment Violet 23. Further examples for blue pigments are such of C.I. Blue 15:3, 15:4, 15:6, 16 and 60, i.e. Phthalocyanine C. I. PigmentBlue 15:3, or Phthalocyanine C. I. Pigment Blue 15:6. Other suitablepigments are such of C. I. Pigment Blue 22, 28, C. I. Pigment Violet14,19, 23, 29, 32, 37,177 and C. I. Orange 73.

The pigment of the black matrix photopolymeric composition preferablycomprises at least one member selected from the group consisting ofcarbon, titanium black and iron oxide. However, a mixture of otherpigments which, in total, give the black appearance, can also be used.For example, also C. I. Pigment Black 1 and 7 can be used alone or incombination.

For any color, combinations of more than two pigments can also be used.Especially suitable in color filter applications are powdery processedpigments prepared by finely dispersing the above mentioned pigments intoa resin.

The concentration of the pigment in the total solid component (pigmentsof various colors and resin) is for example in the range of 5% to 80% byweight, in particular in the range of 20% to 45% by weight.

The pigments in the color filter resist composition have preferably amean particle diameter smaller than the wavelength of visible light (400nm to 700 nm). Particularly preferred is a mean pigment diameter of <100nm.

If necessary, the pigments may be stabilized in the photosensitivecomposition by pretreatment of the pigments with a dispersant to improvethe dispersion stability of the pigment in the liquid formulation.

Examples for color filter resists, the composition of such resists andthe processing conditions are given by T. Kudo et al., Jpn. J. Appl.Phys. Vol. 37 (1998) 3594; T. Kudo et al., J. Photopolym. Sci. Technol.Vol 9 (1996) 109; K. Kobayashi, Solid State Technol. Nov. 1992, p.S15-S18; U.S. Pat. No. 5,368,976; U.S. Pat. No. 5,800,952; U.S. Pat. No.5,882,843; U.S. Pat. No. 5,879,855; U.S. Pat. No. 5,866,298; U.S. Pat.No. 5,863,678; JP 06-230212-A; EP 320264; JP 09-269410-A; JP10-221843-A; JP 01-090516-A; JP 10-171119-A, U.S. Pat. No. 5,821,016,U.S. Pat. No. 5,847,015, U.S. Pat. No. 5,882,843, U.S. Pat. No.5,719,008, EP 881541, or EP 902327.

The photoinitiators of the present invention can be used in color filterresists, for example, such as those given as examples above, or canpartially or fully replace the known photoinitiators in such resists. Itis understood by a person skilled in the art that the use of the newphotoinitiators of the present invention is not limited to the specificbinder resins, crosslinkers and formulations of the color filter resistexamples given hereinbefore but can be used in conjunction with anyradically polymerizable component in combination with a dye or colorpigment or latent pigment to form a photosensitive color filter ink orcolor filter resist.

Accordingly, subject of the invention also is a color filter prepared byproviding red, green and blue (RGB) colour elements and, optionally ablack matrix, all comprising a photosensitive resin and a pigment on atransparent substrate and providing a transparent electrode either onthe surface of the substrate or on the surface of the color filterlayer, wherein said photosensitive resin comprises a polyfunctionalacrylate monomer, an organic polymer binder and a photopolymerizationinitiator of formula I, II, III, IV or V as described above. The monomerand binder components, as well as suitable pigments are as describedabove. In the manufacture of color filters the transparent electrodelayer can either be applied on the surface of the transparent substrateor can be provided on the surface of the red, green and blue pictureelements and the black matrix. The transparent substrate is for examplea glass substrate which can additionally have an electrode layer on itssurface. It is preferred to apply a black matrix between the color areasof different color in order to improve the contrast of a color filter.

Instead of forming a black matrix using a photosensitive composition andpatterning the black photosensitive composition photolithographically bypatternwise exposure (i.e. through a suitable mask) to form the blackpattern separating the red green and blue coloured areas on thetranparent substrate it is alternatively possible to use an inorganicblack matrix. Such inorganic black matrix can be formed from deposited(i.e. sputtered) metal (i.e. chromium) film on the transparent substrateby a suitable imaging process, for example utilizing photolithographicpatterning by means of an etch resist, etching the inorganic layer inthe areas not protected by the etch resist and then removing theremaining etch resist.

There are different methods known how and at which step in the colorfilter manufacturing process the black matrix can be applied. It caneither be applied directly on the transparent substrate prior toformation of the red, green and blue (RGB) colour filter as alreadymentioned above, or it can be applied after the RGB colour filter isformed on the substrate. In a different embodiment of a color filter fora liqid crystal display, according to U.S. Pat. No. 5,626,796, the blackmatrix can also be applied on the substrate opposite to the RGB colorfilter element-carrying substrate, which is separated from the former bya liquid crystal layer.

If the transparent electrode layer is deposited after applying the RGBcolor filter elements and-optionally-the black matrix, an additionalovercoat film as aprotective layer can be applied on the color filterlayer prior to deposition of the electrode layer, for example, asdescribed in U.S. Pat. No. 5,650,263.

To form an overcoat layer of a color filter, photosensitive resin orthermosetting resin compositions are employed. The photosensitivecomposition of the present invention can also be used to form suchovercoat layers, because a cured film of the composition is excellent inflatness, hardness, chemical and thermal resistance, transparencyespecially in a visible region, adhesion to a substrate, and suitabilityfor forming a transparent conductive film, e.g., an ITO film, thereon.In the production of a protective layer, there has been a demand thatunnecessary parts of the protective layer, for example on scribing linesfor cutting the substrate and on bonding pads of solid image sensorsshould be removed from the substrate as described in JP57-42009-A,JP1-130103-A and JP1-134306-A. In this regard, it is difficult toselectively form a protective layer with good precision using theabove-mentioned thermosetting resins. The photosensitive composition,however, allows to easily remove the unnecessary parts of the protectivelayer by photolithography.

It is obvious to those skilled in the art, that the photosensitivecompositions of the present invention can be used for generating red,green and blue color pixels and a black matrix, for the manufacture of acolor filter, regardless of the above described differences inprocessing, regardless, of additional layers which can be applied andregardless of differences in the design of the color filter. The use ofa composition according to the present invention to form coloredelements shall not be regarded as limited by different designs andmanufacturing processes of such color filters.

Preferably, the color filter resist composition according to the presentinvention contains additionally at least one addition polymerizablemonomeric compound as component (a). For example, the followingcompounds can be used singly or in combination with the other monomersas the addition-polymerizable monomer having an ethylenicallyunsaturated double bond used in the present invention. Specifically,they include t-butyl(meth)acrylate, ethylene glycol di(meth)acrylate,2-hydroxypropyl (meth)acrylate, triethylene glycol di(meth)acrylate,trimethylolpropane tri(meth)acrylate, 2-ethyl-2-butylpropanedioldi(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritoltetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate,dipentaerythritol penta(meth)acrylate, polyoxyethylatedtrimethylolpropane tri(meth)acrylate,tris(2-(meth)acryloyloxyethyl)isocyanurate, 1,4-diisopropenyl-benzene,1,4-di-hydroxybenzene (meth)acrylate, decamethylene glycoldi(meth)acrylate, styrene, diallyl fumarate, triallyl trimellitate,lauryl (meth)acrylate, (meth)acrylamide, and xylenebis(meth)acrylamide.Further, there can be used a reaction product of a compound having ahydroxyl group, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl(meth)acrylate, and polyethylene glycol mono(meth)acrylate withdiisocyanate such as hexamethylenediisocyanate, toluenediisocyanate, andxylenediisocyanate. Particularly preferred are pentaerythritoltetra-acrylate, dipentaerythritol hexaacrylate, dipenta-erythritolpentaacrylate, and tris(2-acyloyl-oxyethyl)-isocyanurate.

In a color filter resist composition the whole amount of the monomerscontained in the photopolymerizable composition is preferably 5 to 80%by weight, in particular 10 to 70% by weight based on the whole solidcontents of the composition, i.e. the amount of all components withoutthe solvent(s).

As the binder used in the color filter resist composition, which issoluble in an alkaline aqueous solution and insoluble in water, forexample, a homopolymer of a polymerizable compound having one or moreacid groups and one or more polymerizable unsaturated bonds in themolecule, or a copolymer of two or more kinds thereof, and a copolymerof one or more polymerizable compounds having one or more unsaturatedbonds copolymerizable with these compounds and containing no acid group,can be used. Such compounds can be obtained by copolymerizing one ormore kinds of a low molecular compound having one or more acid groupsand one or more polymerizable unsaturated bonds in the molecule with oneor more polymerizable compounds having one or more unsaturated bondscopolymerizable with these compounds and containing no acid group.Examples of acids groups are, a —COOH group, a —SO₃H group, a —SO₂NHCO—group, a phenolic hydroxy group, a —SO₂NH— group, and a —CO—NH—CO—group. Among those, a high molecular compound having a —COOH group isparticularly preferred.

Preferably, the organic polymer binder in the color filter resistcomposition comprises an alkali soluble copolymer comprising, asaddition polymerizable monomer units, at least an unsaturated organicacid compound such as acrylic acid, methacrylic acid and the like. It ispreferred to use as a further co-monomer for the polymer binder anunsaturated organic acid ester compound such as methyl acrylate, ethyl(meth)acrylate, benzyl (meth)acrylate, styrene and the like to balanceproperties such as alkaline solubility, adhesion rigidity, chemicalresistance etc.

The organic polymer binder can either be a random co-polymer or ablock-co-polymer, for example, such as described in U.S. Pat. No.5,368,976.

Examples of polymerizable compounds having one or more acid group andone or more polymerizable unsaturated bond in the molecule include thefollowing compounds: Acrylic acid, methacrylic acid, itaconic acid,crotonic acid, maleic acid, vinylbenzoic acid, and cinnamic acid areexamples of the polymerizable compounds having one or more —COOH groupsand one or more polymerizable unsaturated bonds in a molecule.Vinylbenzenesulfonic acid and 2-(meth)acrylamide-2-methylpropanesulfonicacid are examples of the polymerizable compounds having one or more—SO₃H groups and one or more polymerizable unsaturated bonds.

N-methylsulfonyl (meth)acrylamide, N-ethylsulfonyl (meth)acrylamide,N-phenylsulfonyl (meth)acrylamide, and N-(p-methylphenylsulfonyl)(meth)acrylamide are examples of the polymerizable compounds having oneor more —SO₂NHCO— groups and one or more polymerizable unsaturatedbonds.

Examples of polymerizable compounds having one or more phenolic hydroxygroups and one or more polymerizable unsaturated bonds in a moleculeinclude hydroxyphenyl (meth)acrylamide, dihydroxyphenyl(meth)acrylamide, hydroxyphenyl-carbonyloxyethyl (meth)acrylate,hydroxyphenyloxyethyl (meth)acrylate, hydroxyphenylthioethyl(meth)acrylate, dihydroxyphenylcarbonyloxyethyl (meth)acrylate,dihydroxyphenyloxyethyl (meth)acrylate, and dihydroxy-phenylthioethyl(meth)acrylate.

Examples of the polymerizable compound having one or more —SO₂NH— groupsand one or more polymerizable unsaturated bonds in the molecule includecompounds represented by formula (a) or (b):CH₂═CHA₁-Y₁-A₂-SO₂—NH-A₃  (a)CH₂═CHA₄-Y₂-A₅-NH—SO₂-A₆  (b)wherein Y₁ and Y₂ each represents —COO—, —CONA₇-, or a single bond; A₁and A₄ each represents H or CH₃; A₂ and A₅ each representsC₁-C₁₂alkylene optionally having a substituent, cycloalkylene, arylene,or aralkylene, or C₂-C₁₂alkylene into which an ether group and athioether group are inserted, cycloalkylene, arylene, or aralkylene; A₃and A₆ each represents H, C₁-C₁₂alkyl optionally having a substituent, acycloalkyl group, an aryl group, or an aralkyl group; and A₇ representsH, C₁-C₁₂alkyl optionally having a substituent, a cycloalkyl group, anaryl group, or an aralkyl group.

The polymerizable compounds having one or more —CO—NH—CO— group and oneor more polymerizable unsaturated bond include maleimide andN-acryloyl-acrylamide. These polymerizable compounds become the highmolecular compounds comprising a —CO—NH—CO— group, in which a ring isformed together with a primary chain by polymerization. Further, amethacrylic acid derivative and an acrylic acid derivative each having a—CO—NH—CO— group can be used as well. Such methacrylic acid derivativesand the acrylic acid derivatives include, for example, a methacrylamidederivative such as N-acetylmethacrylamide, N-propionylmethacrylamide,N-butanoylmethacrylamide, N-pentanoylmethacrylamide,N-decanoylmethacrylamide, N-dodecanoylmethacrylamide,N-benzoylmethacrylamide, N-(p-methylbenzoyl)methacryl-amide,N-(p-chlorobenzoyl)methacrylamide, N-(naphthyl-carbonyl)methacrylamide,N-(phenylacetyl)-methacryl-amide, and 4-methacryloylaminophthalimide,and an acrylamide derivative having the same substituent as these. Thesepolymerizable compounds polymerize to be compounds having a —CO—NH—CO—group in a side chain.

Examples of polymerizable compounds having one or more polymerizableunsaturated bond and containing no acid group include a compound havinga polymerizable unsaturated bond, selected from (meth)acrylates,(meth)acrylamides, an acrylic compound, vinyl ethers, vinyl esters,styrenes, and crotonates, and specifically, include (meth)acrylates suchas alkyl (meth)acrylate or substituted alkyl (meth)acrylate (forexample, methyl (meth)acrylate, ethyl (meth)acrylate, propyl(meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, amyl(meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate,ethylhexyl (meth)acrylate, octyl (meth)acrylate, t-octyl (meth)acrylate,chloro-ethyl (meth)acrylate, allyl (meth)acrylate, 2-hydroxy-ethyl(meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl(meth)acrylate, 2,2-dimethyl-3-hydroxy-propyl (meth)acrylate,5-hydroxypentyl (meth)acrylate, trimethylolpropane mono (meth)acrylate,pentaerythritol mono (meth)acrylate, benzyl (meth)acrylate,methoxy-benzyl (meth)acrylate, chlorobenzyl (meth)acrylate, furfuryl(meth)acrylate, tetrahydrofurfuryl (meth)acrylate, phenoxyethyl(meth)acrylate, and aryl (meth)acrylate (for example, phenyl(meth)acrylate, cresyl (meth)acrylate, and naphthyl (meth)acrylate);(meth)acrylamides such as (meth)acryl-amide, N-alkyl(meth)acrylamide(the alkyl group includes, for example, methyl, ethyl, propyl, butyl,t-butyl, heptyl, octyl, ethylhexyl, cyclohexyl, hydroxyethyl, andbenzyl), N-aryl(meth)acrylamide (the aryl group includes, for example,phenyl, tolyl, nitrophenyl, naphthyl, and hydroxyphenyl),N,N-dialkyl(meth)acryl-amide (the alkyl group includes, for example,methyl, ethyl, butyl, isobutyl, ethylhexyl, and cyclohexyl), N,N-diaryl(meth)acrylamide (the aryl group includes, for example, phenyl),N-methyl-N-phenyl (meth)acryl-amide, N-hydroxyethyl-N-methyl(meth)acrylamide, N-2-acetoamidethyl-N-acetyl(meth)acrylamide,N-(phenyl-sulfonyl)(meth)acrylamide, andN-(p-methylphenyl-sulfonyl)(meth)-acrylamide;

an allyl compound such as allyl esters (for example, allyl acetate,allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allylstearate, allyl benzoate, allyl acetoacetate, and allyl lactate), andallyloxyethanol;

vinyl ethers such as alkyl vinyl ether (the alkyl group includes, forexample, hexyl, octyl, decyl, ethylhexyl, methoxyethyl, ethoxyethyl,chloroethyl, 1-methyl-2,2-dimethylpropyl, 2-ethylbutyl, hydroxyethyl,hydroxyethoxyethyl, dimethylaminoethyl, diethylamino-ethyl,butylaminoethyl, benzyl, and tetrahydrofurfuryl), and vinyl aryl ether(the aryl group includes, for example, phenyl, tolyl, chlorophenyl,2,4-dichloro-phenyl, naphthyl, and anthranyl); vinyl esters such asvinyl butylate, vinyl isobutylate, vinyl trimethylacetate, vinyldiethyl-acetate, vinyl barate, vinyl caproate, vinyl chloro-acetate,vinyl dichloroacetate, vinyl methoxyacetate, vinyl butoxyacetate, vinylphenylacetate, vinyl aceto-acetate, vinyl lactate,vinyl-b-phenylbutylate, vinyl cyclohexylcarboxylate, vinyl benzoate,vinyl salicylate, vinyl chlorobenzoate, vinyl tetrachlorobenzoate, andvinyl naphthoate;

styrenes such as styrene, alkylstyrene (for example, methylstyrene,dimethylstyrene, trimethyl-styrene, ethylstyrene, diethylstyrene,isopropylstyrene, butylstyrene, hexylstyrene, cyclohexylstyrene,decyl-styrene, benzylstyrene, chloromethylstyrene,trifluoro-methylstyrene, ethoxymethylstyrene, andacetoxymethyl-styrene), alkoxystyrene (for example, methoxystyrene,4-methoxy-3-methylstyrene, and dimethoxystyrene), and halogenostyrene(for example, chlorostyrene, dichlorostyrene, trichlorostyrene,tetrachlorostyrene, penta-chlorostyrene, bromostyrene, dibromostyrene,iodostyrene, fluorostyrene, trifluorostyrene,2-bromo-4-trifluoromethylstyrene, and4-fluoro-3-trifluoromethyl-styrene);

crotonates such as alkyl crotonate (for example, butyl crotonate, hexylcrotonate, and glycerine monocrotonate); dialkyl itaconates (forexample, dimethyl itaconate, diethyl itaconate, and dibutyl itaconate);dialkyl maleates or fumarates (for example, dimethyl maleate and dibutylfumarate); and (meth)acrylonitrile.

There can be used as well hydroxystyrene homo- or co-polymers or anovolak type phenol resin, for example, poly(hydroxystyrene) andpoly(hydroxystyrene-co-vinylcyclohexanol), a novolak resin, a cresolnovolak resin, and a halogenated phenol novolak resin. Morespecifically, it includes, for example, the methacrylic acid copolymers,the acrylic acid copolymers, the itaconic acid copoymers, the crotonicacid copolymers, the maleic anhydride co-polymers, for example, withstyrene as a co-monomer, and maleic acid copolymers, and partiallyesterified maleic acid copolymers each described in, for example, JP59-44615-B4 (the term “JP-B4” as used herein refers to an examinedJapanese patent publication), JP 54-34327-B4, JP 58-12577-B4, and JP54-25957-B4, JP 59-53836-A, JP 59-71048-A, JP 60-159743-A, JP60-258539-A, JP 1-152449-A, JP 2-199403-A, and JP 2-199404-A, and whichcopolymers can be further reacted with an amine, as e.g disclosed inU.S. Pat. No. 5,650,263; further, a cellulose derivative having acarboxyl group on a side chain can be used, and particularly preferredare copolymers of benzyl (meth)acrylate and (meth)acrylic acid andcopolymers of benzyl (meth)acrylate, (meth)acrylic acid and othermonomers, for example as described in U.S. Pat. No. 4,139,391, JP59-44615-B4, JP 60-159743-A and JP 60-258539-A.

With respect to those having carboxylic acid groups among the aboveorganic binder polymers, it is possible to react some or all of thecarboxylic acid groups with glycidyl(meth)acrylate or anepoxy(meth)acrylate to obtain photopolymerizable organic binder polymersfor the purpose of improving the photosensitivity, coating filmstrength, the coating solvent and chemical resistance and the adhesionto the substrate. Examples are disclosed in, JP 50-34443-B4 and JP50-34444-B4, U.S. Pat. No. 5,153,095, by T. Kudo et al. in J. Appl.Phys., Vol. 37 (1998), p. 3594-3603, U.S. Pat. No. 5,677,385, and U.S.Pat. No. 5,650,233.

The weight-average molecular weight of the binders is preferably 500 to1,000,000, e.g. 3,000 to 1,000,000, more preferably 5,000 to 400,000.

These compounds may be used singly or as a mixture of two or more kinds.The content of the binder in the light-sensitive resin composition ispreferably 10 to 95 weight %, more preferably 15 to 90 weight % based onthe whole solid matters.

Further, in the color filter the total solid component of each color maycontain an ionic impurity-scavenger, e.g. an organic compound having anepoxy group. The concentration of the ionic impurity scavenger in thetotal solid component generally is in the range from 0.1% by weight to10% by weight.

Examples of color filters, especially with respect to the abovedescribed combinations of pigments and ionic impurity scavenger aregiven in EP 320264. It is understood, that the photoinitiators accordingto the present invention, i.e. the compounds of the formulae I, II, IIIand IV in the color filter formulations described in EP 320264 canreplace the triazine initiator compounds.

The compositions according to this invention can comprise additionally acrosslinking agent which is activated by an acid, for example asdescribed in JP 10 221843-A, and a compound which generates acidthermally or by actinic radiation and which activates a crosslinkingre-action.

The compositions according to this invention can also comprise latentpigments which are transformed into finely dispersed pigments during theheat treatment of the latent pigment containing photosensitive patternor coating. The heat treatment can be performed after exposure or afterdevelopment of the latent pigment-containing photoimageable layer. Suchlatent pigments are soluble pigment precursors which can be transformedinto insoluble pigments by means of chemical, thermal, photolytic orradiation induced methods as described, for example, in U.S. Pat. No.5,879,855. This transformation of such latent pigments can be enhancedby adding a compound which generates acid at actinic exposure or byadding an acidic compound to the composition. Therefore, a color filterresist can also be prepared, which comprises a latent pigment in acomposition according to this invention.

The photo-sensitive composition of the present invention can suitably beused for forming a color filter but will not be limited to thisapplication. It is useful as well for a recording material, a resistmaterial, a protective layer, a dielectric layer, in displayapplications and display elements, a paint, and a printing ink.

The photosensitive compositions according to the invention are alsosuitable for manufacturing interlayer insulating layers or dielectriclayers in a liquid crystal display, and more particularly in areflection type liquid crystal display including an active matrix typedisplay having a thin film transistor(TFT) as a switching device, and apassive matrix type without a switching device.

In recent years, liquid crystal displays have, for example, been widelyused for pocket-type TV sets and terminal devices for communication byvirtue of its small thickness and light weight. A reflection type liquidcrystal display without necessity of using a back light is in particularin demand because it is ultra-thin and light-weight, and it cansignificantly reduce power consumption. However, even if a back light isremoved out of a presently available transmission type color liquidcrystal display and a light reflection plate is added to a lower surfaceof the display, it would cause a problem in that the efficiency ofutilizing lights is low, and it is not possible to have practicalbrightness.

As a solution to this problem, there have been suggested variousreflection type liquid crystal displays for enhancing an efficiency ofutilizing lights. For instance, a certain reflection type liquid crystaldisplay is designed to include a pixel electrode having reflectionfunction.

The reflection type liquid crystal display includes an insulatingsubstrate and an opposing substrate spaced away from the insulatingsubstrate. A space between the substrates is filled with liquidcrystals. A gate electrode is formed on the insulating substrate, andboth the gate electrode and the insulating substrate are covered with agate insulating film. A semiconductor layer is then formed on the gateinsulating film above the gate electrode. A source electrode and a drainelectrode are also formed on the gate insulating film in contact withthe semiconductor layer. The source electrode, the drain electrode, thesemiconductor layer, and the gate electrode cooperate with one anotherto thereby constitute a bottom gate type TFT as a switching device.

An interlayer insulating film is formed covering the source electrode,the drain electrode, the semiconductor layer, and the gate insulatingfilm therewith. A contact hole is formed throughout the interlayerinsulating film on the drain electrode. A pixel electrode made ofaluminum is formed on both the interlayer insulating film and an innersidewall of the contact hole. The drain electrode of the TFT iseventually in contact with the pixel electrode through the interlayerinsulating film. The interlayer insulating layer is generally designedto have a roughened surface by which the pixel electrode acts as areflection plate which diffuses lights to get a wider angle forviewing(angle of visibility).

The reflection type liquid crystal display remarkably enhances anefficiency of using lights by virtue that the pixel electrode acts as alight reflection plate.

In the above-mentioned reflection type liquid crystal display, theinterlayer insulating film is designed to have projections and recessesby photolithography. To form and control a fine shape of the projectionsand recesses in micrometer order for surface roughness and to formcontact holes, photolithography methods using positive and negativephotoresists are used. For these resists the compositions according tothe invention are especially suitable.

The photosensitive compositions according to the invention can furtherbe used for manufacturing spacers, which control a cell gap of theliquid crystal part in liquid crystal display panels. Since theproperties of light transmitted or reflected through the liquid crystallayer in a liquid crystal display are dependent on the cell gap, thethickness accuracy and uniformity over the pixel array are criticalparameters for the performance of the liquid crystal display unit. In aliquid crystal cell, the spacing between the substrates in the cell ismaintained constant by sparsely distributing glass or polymer spheresabout several micrometers in diameter as spacers between the substrates.The spacers are thus held between the substrates to maintain thedistance between the substrates at a constant value. The distance isdetermined by the diameter of the spacers. The spacers assure theminimum spacing between the substrates; i.e., they prevent a decrease indistance between the substrates. However, they cannot prevent thesubstrates from being separated apart from each other, i.e., theincrease in distance between the substrates. Additionally, this methodof using spacer beads has problems of the uniformity in the diameter ofspacer beads and difficulty in the even dispersion of spacer beads onthe panel, as well as nonuniform orientation and decrease in brightnessand/or optical aperture depending on the location of spacers on pixelarray region. Liquid crystal displays having a large image display areahave recently been attracting much attention. However, the increase inthe area of a liquid crystal cell generally produces the distortion ofthe substrates constituting the cell. The layer structure of the liquidcrystal tends to be destroyed due to the deformation of the substrate.Thus, even when spacers are used for maintaining the spacing between thesubstrates constant, a liquid crystal display having a large imagedisplay area is unfeasible because the display experiences disturbances.Instead of the above spacer sphere dispersion method, a method offorming columns in the cell gap as spacers has been proposed. In thismethod, columns of a resin are formed as spacers in the region betweenthe pixel array region and the counter electrode to form a prescribedcell gap. Photosensitive materials having adhesive properties withphotolithography are commonly used, for instance, in the manufacturingprocess of color filters. This method is advantageous compared with theconventional method using spacer beads in the points that location,number and height of the spacers may be controlled freely. In a colorliquid crystal display panel, such spacers are formed in the nonimagingarea under black matrix of color filter elements. Therefore, the spacersformed using photosensitive compositions do not decrease brightness andoptical aperture.

Photosensitive compositions for producing protective layer with spacersfor color filters are disclosed in JP 2000-81701-A and dry film typephotoresists for spacer materials are also disclosed in JP 11-174459-Aand JP 11-174464-A. As described in the documents, the photosensitivecompositions, liquid and dry film photoresists, are comprising at leastan alkaline or acid soluble binder polymer, a radically polymerizablemonomer, and a radical initiator. In some cases, thermally crosslinkablecomponents such as epoxide and carboxylic acid may additionally beincluded.

The steps to form spacers using a photosensitive composition are asfollows: a photosensitive composition is applied to the substrate, forinstance a color filter panel and after the substrate is prebaked, it isexposed to light through a mask. Then, the substrate is developed with adeveloper and patterned to form the desired spacers. When thecomposition contains some thermosetting components, usually a postbakingis carried out to thermally cure the composition.

The photocurable compositions according to the invention are suitablefor producing spacers for liquid crystal displays (as described above)because of their high sensitivity.

The photosensitive compositions according to the invention are alsosuitable for manufacturing microlens arrays used in liquid crystaldisplay panels, image sensors and the like. Microlenses are microscopicpassive optical components that fit on active optoelectronic devicessuch as detectors, displays, and light emitting devices(light-emittingdiodes, transversal and vertical cavity lasers) to improve their opticalinput or output quality. The areas of applications are wide and coverareas such as telecommunications, information technology, audio-visualservices, solar cells, detectors, solid-state light sources, and opticalinterconnects.

Present optical systems use a variety of techniques to obtain efficientcoupling between microlenses and microoptical devices.

The microlens arrays are used for condensing illuminating light on thepicture element regions of a nonluminescent display device, such as aliquid crystal display devices, to increase the brightness of thedisplay, for condensing incident light or as a means for forming animage on the photoelectric conversion regions of a line image sensorused for example in facsimiles and the like to improve the sensitivityof these devices, and for forming an image to be printed on aphotosensitive means used in liquid crystal printers or light emittingdiode (LED) printers.

The most common application is their use to improve the efficiency ofphotodetector arrays of a solid-state image sensing device such as acharge coupled device (CCD). In a detector array, the collection of asmuch light as possible in each detector element or pixel is wanted. If amicrolens is put on top of each pixel, the lens collects incoming lightand focuses it onto an active area that is smaller than the size of thelens.

According to the prior-art, microlens arrays can be produced by avariety of methods;

-   (1) A method for obtaining convex lenses wherein a pattern of the    lenses in a planar configuration is drawn on a thermoplastic resin    by a conventional photolithographic technique or the like, and then    the thermoplastic resin is heated to a temperature above the    softening point of the resin to have flowability, thereby causing a    sag in the pattern edge (so called “reflowing”) (see, e.g., JP    60-38989-A, JP 60-165623-A, JP 61-67003-A, and JP 2000-39503-A). In    this method, when the thermoplastic resin used is photosensitive, a    pattern of the lenses can be obtained by exposure of this resin to    light.-   (2) A method for forming a plastic or glass material by the use of a    mold or a stamper. As lens material, a photocurable resin and a    thermosetting resin can be used in this method (see, e.g.,    W099/38035).-   (3) A method for forming convex lenses on the basis of a phenomenon    in which when a photosensitive resin is exposed to light in a    desired pattern by the use of an aligner, unreacted monomers move    from the unexposed regions to the exposed regions, resulting in a    swell of the exposed regions (see, e.g., Journal of the Research    Group in Microoptics Japanese Society of Applied Physics, Colloquium    in Optics, Vol. 5, No. 2, pp. 118-123 (1987) and Vol. 6, No. 2, pp.    87-92(1988)).

On the upper surface of a supporting substrate, a photosensitive resinlayer is formed. Thereafter, with the use of a separate shading mask,the upper surface of the photosensitive resin layer is illuminated withlight from a mercury lamp or the like, so that the photosensitive resinlayer is exposed to the light. As a result, the exposed portions of thephotosensitive resin layer swell into the shape of convex lenses to formthe light condensing layer having a plurality of microlens.

-   (4) A method for obtaining convex lenses wherein a photosensitive    resin is exposed to light by a proximity exposure technique in which    a photomask is not brought into contact with the resin, to cause a    blur at the pattern edge, so that the amount of photochemical    reaction products is distributed depending upon the degree of    blurring at the pattern edge (see, e.g., JP 61-153602-A).-   (5) A method for generating a lens effect wherein a photosensitive    resin is exposed to light with a particular intensity distribution    to form a distribution pattern of refractive index depending upon    the light intensity (see, e.g., JP 60-72927-A and JP 60-166946-A).    The photosensitive compositions according to the invention can be    used in any one of the above-mentioned methods to form microlens    arrays using photocurable resin compositions.

A particular class of techniques concentrates on forming microlenses inthermoplastic resins like photoresist. An example is published byPopovic et al. in the reference SPIE 898, pp.23-25 (1988). Thetechnique, named reflow technique, comprises the steps of defining thelenses' footprint in a thermoplastic resin, e.g. by photolithography ina photosensitive resin like a photoresist, and subsequently heating thismaterial above its reflow temperature. The surface tension draws theisland of photoresist into a spherical cap with a volume equal to theoriginal island before the reflow. This cap is a plano-convex microlens.Advantages of the technique are, amongst others, the simplicity, thereproducibility, and the possibility of integration directly on top of alight-emitting or light-detecting optoelectronic device. In some cases,an overcoat layer is formed on the patterned lens units with arectangular shape prior to reflowing to avoid a sagging of the island ofthe resin in the middle without reflow into a spherical cap in thereflow step. The overcoat acts as a permanent protective layer. Thecoating layer is also made of a photosensitive composition.

Microlens arrays can also be fabricated by the use of a mold or astamper as, for example, disclosed in EP0932256A2. A process ofmanufacturing the planar microlens array is as follows: a release agentis coated on a shaping surface of a stamper on which convex portions aredensely arranged, and a photocurable synthetic resin material having ahigh refractive index is set on the shaping surface of the stamper.Next, the base glass plate is pushed onto the synthetic resin material,thereby spreading the synthetic resin material, and the synthetic resinmaterial is cured by irradiating with ultraviolet radiation or byheating and is shaped to form the convex microlenses. Thereafter thestamper is peeled off. Then, a photocurable synthetic resin materialhaving a low refractive index is additionally coated onto the convexmicrolenses as an adhesive layer and a glass substrate which is madeinto a cover glass plate is pushed onto the synthetic resin material,thereby spreading the same. The synthetic resin material is then curedand finally the planar microlens array is formed.

As disclosed in U.S. Pat. No. 5,969,867, a similar method using a moldis applied for the production of a prism sheet, which is used as a partof backlight units for color liquid crystal display panels to enhancethe brightness. A prism sheet forming a prism row on one side is mountedon the light-emitting surface of the backlight. For fabricating a prismsheet, an active energy raycurable composition is cast and spread in alens mold which is made of metal, glass or resin and forms the lensshape of the prism row, etc., after which a transparent substrate sheetis placed onto it and active energy rays from an active energyray-emitting source are irradiated through the sheet for curing. Theprepared lens sheet is then released from the lens mold to obtain thelens sheet.

The active energy ray-curable composition used to form the lens sectionmust have a variety of properties, including adhesion to the transparentsubstrate, and suitable optical characteristics.

Lenses at least with some photoresists in the prior art are notdesirable for some applications since the optical transmittance in theblue end of the optical spectrum is poor.

Because the photocurable compositions according to the invention havelow yellowing properties, both thermally and photochemically, they aresuitable for the production of microlens arrays as described above.

The novel radiation-sensitive compositions are also suitable forphoto-lithographic steps used in the production process of plasmadisplay panels (PDP), particularly for the imaging forming process ofbarrier rib, phosphor layer and electrodes.

The PDP is a planar display for displaying images and information byvirtue of the emission of light by gas discharge. By the construction ofpanel and the method of operation, it is known in two types, i.e. DC(direct current) type and AC (alternating current) type.

By way of example, the principle of the DC type color PDP will bebriefly explained. In the DC type color PDP, the space interveningbetween two transparent substrates (generally glass plates) is dividedinto numerous minute cells by latticed barrier ribs interposed betweenthe transparent substrates. In the individual cells a discharge gas,such as He or Xe, is sealed. On the rear wall of each cell there is aphosphor layer which, on being excited by the ultraviolet lightgenerated by the discharge of the discharge gas, emits visible light ofthree primary colors. On the inner faces of the two substrates,electrodes are disposed as opposed to each other across the relevantcells. Generally, the cathodes are formed of a film of transparentelectroconductive material such as NESA glass. When a high voltage isapplied between these electrodes formed on the fore wall and the rearwall, the discharge gas which is sealed in the cells induces plasmadischarge and, by virtue of the ultraviolet light radiated consequently,incites the fluorescent elements of red, blue, and green colors to emitlights and effect the display of an image. In the full-color displaysystem, three fluorescent elements severally of the three primary colorsof red, blue, and green mentioned above jointly form one pictureelement.

The cells in the DC type PDP are divided by the component barrier ribsof a lattice, whereas those in the AC type PDP are divided by thebarrier ribs which are arranged parallel to each other on the faces ofthe substrates. In either case, the cells are divided by barrier ribs.These barrier ribs are intended to confine the luminous discharge withina fixed area to preclude false discharge or cross talk between adjacentdischarge cells and ensure ideal display.

The compositions according to the invention also find application forthe production of one- or more-layered materials for the image recordingor image reproduction (copies, reprography), which may be mono- orpolychromatic. Furthermore the materials are suitable for color proofingsystems. In this technology formulations containing microcapsules can beapplied and for the image production the radiation curing can befollowed by a thermal treatment. Such systems and technologies and theirapplications are for example disclosed in U.S. Pat. No. 5,376,459.

Photocuring is of great importance for printings, since the drying timeof the ink is a critical factor for the production rate of graphicproducts, and should be in the order of fractions of seconds. UV-curableinks are particularly important for screen printing and offset inks.

As already mentioned above, the novel mixtures are highly suitable alsofor producing printing plates. This application uses, for example,mixtures of soluble linear polyamides or styrene/butadiene and/orstyrene/isoprene rubber, polyacrylates or polymethyl methacrylatescontaining carboxyl groups, polyvinyl alcohols or urethane acrylateswith photopolymerizable monomers, for example acrylamides and/ormethacrylamides, or acrylates and/or methacrylates, and aphotoinitiator. Films and plates of these systems (wet or dry) areexposed over the negative (or positive) of the printed original, and theuncured parts are subsequently washed out using an appropriate solventor aqueous solutions.

Another field where photocuring is employed is the coating of metals, inthe case, for example, of the coating of metal plates and tubes, cans orbottle caps, and the photocuring of polymer coatings, for example offloor or wall coverings based on PVC.

Examples of the photocuring of paper coatings are the colourlessvarnishing of labels, record sleeves and book covers.

Also of interest is the use of the novel photoinitiators for curingshaped articles made from composite compositions. The composite compoundconsists of a self-supporting matrix material, for example a glass fibrefabric, or alternatively, for example, plant fibres [cf. K.-P. Mieck, T.Reussmann in Kunststoffe 85 (1995), 366-370], which is impregnated withthe photocuring formulation. Shaped parts comprising compositecompounds, when produced using the novel compounds, attain a high levelof mechanical stability and resistance. The novel compounds can also beemployed as photocuring agents in moulding, impregnating and coatingcompositions as are described, for example, in EP 7086. Examples of suchcompositions are gel coat resins, which are subject to stringentrequirements regarding curing activity and yellowing resistance, andfibre-reinforced mouldings, for example, light diffusing panels whichare planar or have lengthwise or crosswise corrugation. Techniques forproducing such mouldings, such as hand lay-up, spray lay-up, centrifugalcasting or filament winding, are described, for example, by P. H. Seldenin “Glasfaserverstarkte Kunststoffe”, page 610, Springer VerlagBerlin-Heidelberg-New York 1967. Examples of articles which can beproduced by these techniques are boats, fibre board or chipboard panelswith a double-sided coating of glass fibre-reinforced plastic, pipes,containers, etc. Further examples of moulding, impregnating and coatingcompositions are UP resin gel coats for mouldings containing glassfibres (GRP), such as corrugated sheets and paper laminates. Paperlaminates may be based on urea resins or melamine resins. Prior toproduction of the laminate, the gel coat is produced on a support (forexample a film). The novel photocurable compositions can also be usedfor casting resins or for embedding articles, for example electroniccomponents, etc.

The compositions and compounds according to the invention can be usedfor the production of holographies, waveguides, optical switches whereinadvantage is taken of the development of a difference in the index ofrefraction between irradiated and unirradiated areas.

The use of photocurable compositions for imaging techniques and for theoptical production of information carriers is also important. In suchapplications, as already described above, the layer (wet or dry) appliedto the support is irradiated imagewise, e.g. through a photomask, withUV or visible light, and the unexposed areas of the layer are removed bytreatment with a developer. Application of the photocurable layer tometal can also be carried out by electrodeposition. The exposed areasare polymeric through crosslinking and are therefore insoluble andremain on the support. Appropriate colouration produces visible images.Where the support is a metallized layer, the metal can, followingexposure and development, be etched away at the unexposed areas orreinforced by electroplating. In this way it is possible to produceelectronic circuits and photoresists. When used in image-formingmaterials the novel photoinitiators provide excellent performance ingenerating so called printout images, whereby a color change is induceddue to irradiation. To form such printout images different dyes and/ortheir leuco form are used and examples for such print out image systemscan be fount e.g. in WO 96/41240, EP 706091, EP 511403, U.S. Pat. No.3,579,339, and U.S. Pat. No. 4,622,286.

The invention, as described above, provides compositions for producingpigmented and nonpigmented paints and varnishes, powder coatings,printing inks, printing plates, adhesives, dental compositions,photoresists for electronics like electroplating resist, etch resist,both liquid and dry films, solder resist, as resists to manufacturecolor filters for a variety of display applications or to generatestructures in the manufacturing processes of plasma-display panels (e.g.barrier rib, phosphor layer, electrode), electroluminescence displaysand LCD (e.g. Interlayer insulating layer, spacers, microlens array), ascomposition for encapsulating electrical and electronic components, forproducing magnetic recording materials, micromechanical parts,waveguides, optical switches, plating masks, etch masks, colour proofingsystems, glass fibre cable coatings, screen printing stencils, forproducing three-dimensional objects by means of stereolithography, andas image recording material, especially for holographic recordings,microelectronic circuits, decolorizing materials, decolorizing materialsfor image recording materials, for image recording materials usingmicrocapsules.

Substrates used for photographic information recordings include, forexample, films of polyester, cellulose acetate or polymer-coated papers;substrates for offset printing formes are specially treated aluminium,substrates for producing printed circuits are copper-clad laminates, andsubstrates for producing integrated circuits are, for example, siliconwafers. The layer thickness of the photosensitive layer for photographicmaterials and offset printing forms is generally from about 0.5 μm to 10μm, while for printed circuits it is from 0.1 μm to about 100 μm.Following the coating of the substrates, the solvent is removed,generally by drying, to leave a coat of the photoresist on thesubstrate.

Coating of the substrates can be carried out by applying to thesubstrate a liquid composition, a solution or a suspension. The choiceof solvents and the concentration depend principally on the type ofcomposition and on the coating technique. The solvent should be inert,i.e. it should not undergo a chemical reaction with the components andshould be able to be removed again, after coating, in the course ofdrying. Examples of suitable solvents are ketones, ethers and esters,such as methyl ethyl ketone, isobutyl methyl ketone, cyclopentanone,cyclohexanone, N-methylpyrrolidone, dioxane, tetrahydrofuran,2-methoxyethanol, 2-ethoxyethanol, 1-methoxy-2-propanol,1,2-dimethoxyethane, ethyl acetate, n-butyl acetate, ethyl3-ethoxypropionate, 2-methoxypropylacetate, methyl-3-methoxypropionate,2-heptanone, 2-pentanone, and ethyl lactate.

The solution is applied uniformly to a substrate by means of knowncoating techniques, for example by spin coating, dip coating, knifecoating, curtain coating, brushing, spraying, especially byelectrostatic spraying, and reverse-roll coating, and also by means ofelectrophoretic deposition. It is also possible to apply thephotosensitive layer to a temporary, flexible support and then to coatthe final substrate, for example a copper-clad circuit board, or a glasssubstrate by transferring the layer via lamination.

The quantity applied (coat thickness) and the nature of the substrate(layer support) are dependent on the desired field of application. Therange of coat thicknesses generally comprises values from about 0.1 μmto more than 100 μm, for example 0.1 μm to 1 cm, preferably 0.5 μm to1000 μm.

Following the coating of the substrates, the solvent is removed,generally by drying, to leave an essentially dry resist film of thephotoresist on the substrate.

The photosensitivity of the novel compositions can extend in generalfrom about 150 nm to 600 nm, for example 190-600 nm, (UV-vis region).Suitable radiation is present, for example, in sunlight or light fromartificial light sources. Consequently, a large number of very differenttypes of light sources are employed. Both point sources and arrays(“lamp carpets”) are suitable. Examples are carbon arc lamps, xenon arclamps, low-, medium-, high- and super high- pressure mercury lamps,possibly with metal halide dopes (metal-halogen lamps),microwave-stimulated metal vapour lamps, excimer lamps, superactinicfluorescent tubes, fluorescent lamps, argon incandescent lamps,electronic flashlights, photographic flood lamps, light emitting diodes(LED), electron beams and X-rays. The distance between the lamp and thesubstrate to be exposed in accordance with the invention may varydepending on the intended application and the type and output of lamp,and may be, for example, from 2 cm to 150 cm. Laser light sources, forexample excimer lasers, such as F₂ excimer lasers at 157 nm exposure,KrF excimer lasers for exposure at 248 nm and ArF excimer lasers forexposure at 193 nm are also suitable. Lasers in the visible region canalso be employed.

The term “imagewise” exposure includes both, exposure through aphotomask comprising a predetermined pattern, for example a slide, achromium mask, a stencil mask or a reticle, as well as exposure by meansof a laser or light beam, which for example is moved under computercontrol over the surface of the coated substrate and in this wayproduces an image, and irradiation with computer-controlled electronbeams. It is also possible to use masks made of liquid crystals that canbe addressed pixel by pixel to generate digital images, as is, forexample, described by A. Bertsch, J. Y. Jezequel, J. C. Andre in Journalof Photochemistry and Photobiology A: Chemistry 1997, 107, p. 275-281and by K.-P. Nicolay in Offset Printing 1997, 6, p. 34-37.

Following the imagewise exposure of the material and prior todevelopment, it may be advantageous to carry out thermal treatment for ashort time. After the development a thermal post bake can be performedto harden the composition and to remove all traces of solvents. Thetemperatures employed are generally 50-250° C., preferably 80-220° C.;the duration of the thermal treatment is in general between 0.25 and 60minutes.

The photocurable composition may additionally be used in a process forproducing printing plates or photoresists as is described, for example,in DE 4013358. In such a process the composition is exposed for a shorttime to visible light with a wavelength of at least 400 nm, without amask, prior to, simultaneously with or following imagewise irradiation.

After the exposure and, if implemented, thermal treatment, the unexposedareas of the photosensitive coating are removed with a developer in amanner known per se.

As already mentioned, the novel compositions can be developed by aqueousalkalis or organic solvents. Particularly suitable aqueous-alkalinedeveloper solutions are aqueous solutions of tetraalkylammoniumhydroxides or of alkali metal silicates, phosphates, hydroxides andcarbonates. Minor quantities of wetting agents and/or organic solventsmay also be added, if desired, to these solutions. Examples of typicalorganic solvents, which may be added to the developer liquids in smallquantities, are cyclohexanone, 2-ethoxyethanol, toluene, acetone andmixtures of such solvents. Depending on the substrate also solvents,e.g. organic solvents, can be used as developer, or, as mentioned abovemixtures of aqueous alkalis with such solvents. Particularly usefulsolvents for solvent development include methanol, ethanol, 2-propanol,1-propanol, butanol, diacetone alcohol, ethylene glycol monomethylether, ethylene glycol monoethyl ether, ethylene glycol mono-n-butylether, diethyleneglycol dimethyl ether, propyleneglycol monomethyl etheracetate, ethyl-3-ethoxypropionate, methyl-3-methoxypropionate, n-butylacetate, benzyl alcohol, acetone, methyl ethyl ketone, cyclopentanone,cyclohexanone, 2-heptanone, 2-pentanone, epsilon-caprolactone,gamma-butylolactone, dimethylformamide, dimethylacetamide,hexamethylphosphoramide, ethyl lactate, methyl lactate,epsilon-caprolactam, and N-methyl-pyrrolidinone. Optionally, water canbe added to these solvents up to a level at which still a clear solutionis obtained and at which sufficient solubility of the unexposed areas ofthe light sensitive composition is maintained.

The invention therefore also provides a process for thephotopolymerization of compounds containing ethylenically unsaturateddouble bonds, i.e. monomeric, oligomeric or polymeric compoundscontaining at least one ethylenically unsaturated double bond, whichcomprises adding to these compounds at least one photoinitiator of theformula I, II, III, IV or V as described above and irradiating theresulting composition with electromagnetic radiation, in particularlight of the wavelength 150 to 600 nm, in particular 190-600 nm, withelectron beam, or with X-rays.

The invention further provides a coated substrate which is coated on atleast one surface with a composition as described above, and describes aprocess for the photographic production of relief images, in which acoated substrate is subjected to imagewise exposure and then theunexposed portions are removed with a developer. Imagewise exposure maybe effected by irradiating through a mask or by means of a laser orelectron beam as already described above. Of particular advantage inthis context is the laser beam exposure already mentioned above.

The compounds of the invention have a good thermal stability and lowvolatility, and are also suitable for photopolymerisations in thepresence of air (oxygen). Further, they cause only low yellowing in thecompositions after photopolymerization.

The examples which follow illustrate the invention in more detail. Partsand percentages are, as in the remainder of the description and in theclaims, by weight, unless stated otherwise. Where alkyl radicals havingmore than three carbon atoms are referred to without any mention ofspecific isomers, the n-isomers are meant in each case.

EXAMPLE 1 Synthesis of 4-phenylsulfanyl-benzaldehyde oxime-O-acetate

In formula (I)

R₁═COCH₃

1.a 4-Phenylsulfanyl-benzaldehyde

Into a dimethylformamide (DMF) solution (30 mL) of 11.0 g (100 mmol) ofbenzenethiol is gradually added 14.0 g (132 mmol) of anhydrous Na₂CO₃ at85° C. Then 4-chlorobenzaldehyde (11.3 g, 80.0 mol) is added during 20min. at 85° C. The reaction solution is stirred at this temperature for3 h. After adding H₂O into the reaction mixture, the crude product isextracted with ethyl acetate. The organic layer is washed twice with H₂Oand with brine, dried over anhydrous MgSO₄ and condensed. The residue isapplied to column chromatography on silica gel with acetone-hexane (from1:30 to 1:10) as eluent. 6.05 g of pale yellow oil are obtained (35%).The structure is confirmed by the ¹H-NMR spectrum (CDCl₃). δ [ppm]: 7.24(d, 2H), 7.42-7.44 (m, 3H), 7.53 (dd, 2H), 7.71 (d, 2H), 9.96 (s, 1 H).

1.b 4-Phenylsulfanyl-benzaldehyde oxime

To 4.20 g (19.6 mmol) of 4-phenylsulfanyl-benzaldehyde, 1.50 g (21.6mmol) of H₂NOH—HCl and 2.71 g (33.1 mmol) of sodium acetate are added6.5 mL of H₂O and 19.5 mL of ethanol.

This reaction mixture is heated to reflux for 2 h. After adding H₂O todissolve the precipitated inorganic salt, ethanol is removed byevaporation in vacuo. The crude product is extracted twice with CH₂Cl₂.The CH₂Cl₂ layer is dried over anhydrous MgSO₄ and then condensed.

The residue is applied to column chromatography on silica gel withCH₂Cl₂ and CH₂Cl₂-acetone (10:1) as eluent. 3.86 g of white solid areobtained as the first fraction (86%). This product is assigned to be (E)oxime by ¹H-NMR spectrum (CDCl₃). δ [ppm]: 7.25 (d, 2H), 7.32-7.35 (m,3H), 7.42 (d, 2H), 7.47 (d, 2H), 7.77 (s, 1H), 8.09 (s, 1H); 0.29 g ofwhite solid are obtained as the second fraction (6.6%). This product isassigned to be (Z) oxime by ¹H-NMR spectrum (CDCl₃). δ [ppm]: 7.25 (d,2H), 7.32-7.38 (m, 4H), 7.45 (d, 2H), 7.84 (d, 2H), 9.55 (broad s, 1H)

1.c 4-Phenylsulfanyl-benzaldehyde oxime-O-acetate

1.57 g (6.86 mmol) of 4-phenylsulfanyl-benzaldehyde oxime and 617 mg(7.90 mmol) of acetyl chloride are dissolved in 35 mL of tetrahydrofuran(THF). To this solution are gradually added 1.2 mL (8.61 mmol) oftriethylamine at room temperature. The reaction mixture is stirred atroom temperature for 6 h, and then H₂O is added to dissolve theresulting white solid. The crude product is extracted with ethylacetate. This organic layer is washed twice with saturated NaHCO₃ aq.solution and with brine, followed by drying over anhydrous MgSO₄. Theresidue is applied to column chromatography on silica gel withacetone-hexane (from 1:20 to 1:5) as eluent. 980 mg of white solidmelting at 74-76° C. are obtained (53%). The structure is confirmed bythe ¹H-NMR spectrum (CDCl₃). δ [ppm]: 2.22 (s, 3H), 7.23 (d, 2H), 7.37(d, 2H), 7.38 (t, 1H), 7.45 (d, 2H), 7.62 (d, 2H), 8.29 (s, 1H).

EXAMPLE 2 Synthesis of 2,4-Dimethyl-6-methylsulfanyl-benzaldehyde oximeO-benzoate

In formula I: Ar₁=2,4-dimethyl-6-methylthiophenyl, R₁=benzoyl

2.a 1,3-Dimethyl-5-methylsulfanyl-benzene

10.0 g (0.072 mol) of 3,5-dimethylbenzenethiol, 9.95 g (0.072 mol) ofpotassium carbonate and 0.46 g (1.4 mmol) of tetrabutylammonium bromideare suspended in 20 ml of dimethylsulfoxide under argon. Iodomethane(10.2 g, 0.072 mol) is added dropwise, and the mixture is stirred 16 hat ambient temperature. After pouring the mixture into water, theproduct is extracted with ether, washed with water, dried over sodiumsulfate and concentrated in vacuo. The crude product 9.6 g (0.063 mol;88%) is obtained as a slightly yellow oil, and is used for the next stepwithout further purification.

Elemental analysis: C₉H₁₂S (152.26) C [%] H[%] S[%] calculated: 71.007.94 21.06 found: 70.82 8.01 20.91

2.b 2,4-Dimethyl-6-methylsulfanyl-benzaldehyde

A solution of 1,3-dimethyl-5-methylsulfanyl-benzene (8.95 g; 0.059 mol)in 120 ml of dry dichloromethane is cooled to −15° C. under nitrogen.Titanium tetrachloride (12.9 ml; 0.117 mol) is added dropwise, and theresulting dark solution is cooled to −78° C. Dichloromethyl methylether(7.4 ml; 0.082 mol) is then added dropwise during 30 min. and thetemperature is allowed to rise to 0° C. After stirring for 20 min at 0°C., the reaction mixture is poured onto 80 g of ice and 10 ml ofconcentrated hydrochloric acid. The organic phase is separated, washedneutral with water, dried over magnesium sulfate and evaporated invacuo. A yellow solid (10.5 g; 99%) consisting of a regioisomericmixture of 2,4-dimethyl-6-methylsulfanyl-benzaldehyde and2,6-dimethyl-4-methylsulfanyl-benzaldehyde is obtained, from which thepure 2,4-dimethyl-6-methylsulfanyl-benzaldehyde (6.9 g; 65%), m.p.64-66° C., is isolated by recrystallization from hexane. ¹H-NMR (CDCl₃).δ [ppm]: 10.58 (s, 1H), 6.99 (s, 1H), 6.83 (s, 1H), 2.60 (s, 3H), 2.46(s, 3H), 2.36 (s, 3H).

2.c 2,4-dimethyl-6-methylsulfanyl-benzaldehyde oxime

A solution of hydroxylammonium chloride (1.24 g; 0.018 mol) and sodiumacetate (2.23 g; 0.027 mol) in 5 ml of water and 1.7 ml of ethanol isadded dropwise during 15 min to a refluxing solution of2,4-dimethyl-6-methylsulfanyl-benzaldehyde (3.06 g; 0.017 mol) in 25 mlof ethanol. After 3 h, the precipitate is filtered, washed with waterand dried in vacuo, yielding 1.3 g of the product. The filtrate isevaporated, taken up in diethyl ether, washed with water, dried oversodium sulfate and concentrated by evaporation, yielding an addition-alcrop of 1.7 g of 2,4-dimethyl-6-methylsulfanyl-benzaldehyde oxime. Thetotal yield is 3.0 g (90%). Colorless solid, m.p. 115-117° C.

Elemental analysis: C₁₀H₁₃NOS (195.29) C [%] H[%] N[%] calculated: 61.516.71 7.17 found: 61.79 6.92 7.05

2.d 2,4-Dimethyl-6-methylsulfanyl-benzaldehyde oxime O-benzoate

Benzoyl chloride (1.19 g, 8.4 mmol) and a solution of2,4-dimethyl-6-methylsulfanyl-benzaldehyde oxime (1.50 g; 7.7 mmol) in15 ml of THF are added successively to 5 ml of pyridine at 10° C.,cooling the mixture in an ice bath. After stirring for 2.5 h at ambienttemperature, the mixture is poured into water, extracted with diethylether, washed with 0.5% hydrochloric acid, dried over magnesium sulfateand evaporated. The crude product (2.0 g; 87%) is re-crystallized fromhexane to give an analytically pure sample of2,4-dimethyl-6-methylsulfanyl-benzaldehyde oxime O-benzoate, colorlesscrystals, m.p. 64-66° C. ¹H-NMR (CDCl₃). δ [ppm]: 9.02 (s, 1H), 8.16 (d,2H), 7.61 (m, 1H), 7.50 (m, 2H), 7.06 (s, 1H), 6.95 (s, 1H), 2.57 (s,3H), 2.47 (s, 3H), 2.35 (s, 3H).

EXAMPLES 3-69

The compounds of examples 3-69 are prepared according to the methoddescribed in example 1 from the corresponding aldehydes or ketones. Thecompounds and ¹H-NMR-data are given in tables 1, 2 and 3.

TABLE 1

state/mp [° C.] ¹H-NMR, Example Ar₁ R₁ δ [ppm] 3

CH₃CO 89-902.25(s, 3H)7.41(d, 1H)7.47(t, 2HH)7.63(d, 2H)7.67(d,2H)7.82(d, 2H)8.40(s, 1H) 4

CH₃CO 70-722.23(s, 3H)7.02(d, 2H)7.06(d, 2H)7.20(t, 1H)7.39(t,2H)7.69(d, 2H)8.32(s, 1H) 5

CH₃CO liquid2.22(s, 3H)6.90-7.40(m, 2H)7.09-7.16(m, 2H)7.32-7.40(m,4H)7.44-7.48(m, 1H)8.31(s, 1H) 6

CH₃CO 158-1642.14(s, 3H)2.24(s, 3H)3.36(s, 1H)7.78(s, 4H)8.68(s, 1H) 7

CH₃CO 128-1291.92(s, 3H)2.23(s, 3H)4.91(s, 2H)7.07(d, 1H)7017(dd,1H)7.26(d, 1H)7.70(d, 1H)8.33(s, 1H) 8

Phenyl-CO 79-833.84(s, 3H)3.86(s, 3H)6.99(d, 1H)7.03(d, 1H)7.48(t,2H)7.60(t, 1H)7.63(s, 1H).14(d, 2H)9.01(s, 1H) 9

CH₃CO 83-851.39(t, 3H)1.40(t, 3HH)2.24(s, 3H)4.01(q, 2H)4.05(q,2H)6.85(d, 1H)6.99(dd, 1H)7.46(d, 1H)8.76(s, 1H) 10

CH₃CO 83-852.20(s, 3H)3.87(s, 6HH)6.56(d, 2H)7.34(t, 1H)8.76(s, 1H) 11

CH₃CO 692.24(s, 3H)3.89(s, 6H)7.02(dd, 1H)7.11(t, 1H97.58(dd, 1H)8.72(s,1H) 12

CH₃CO 472.24(s, 3H)3.88(s, 3H)4.57(dd, 2H)5.30(m, 2H)6.05(m, 1H)7.01(dd,1H)7.07(t, 1H)7.57(dd, 1H)8.72(s, 1H) 13

CH₃CO 61-622.19(s, 3H)3.92(s, 3H)5.06(s, 2H)7.04(dd, 1H)7.10(t,1H)7.34-7.39(m, 5H)7.54(dd, 1H)8.53(s, 1H) 14

CH₃CO 115-1162.20(s, 3H)3.86(s, 3H)3.88(s, 6H)6.12(s, 2H)8.73(s, 1H) 15

CH₃CO liquid2.22(s, 3H)3.87(s, 3H)3.91(s, 3H)3.93(s, 3H)6.72(d,1H)7.72(d, 1H)8.80(dd, 1H) 16

CH₃CO 94-952.23(s, 3H)3.90(s, 9H)6.95(s, 2H)8.27(s, 1H) 17

CH₃CO 75-762.24(s, 3H)4.15(s, 2H)7.28-7.32 (m, 6H)7.37(ddd, 1H)7.54(ddd,1H)7.65(dd, 1H)8.27(s, 1H) 18

CH₃CO liquid2.23(s, 3H)7.29-7.39(m, 7H)7.61(ddd, 1H)7.64(dd, 1H)8.28(s,1H) 19

CH₃CO liquid2.23(s, 3H)2.52(s, 3H)7.26(d, 2H)7.65(d, 2H)8.30(s, 1H) 20

C₂H₅O(CO) 58-601.34(t, 3H)4.34(q, 2H)7.23(d, 2H)7.37(d, 2H)7.38(t,1H)7.45(d, 2H)7.59(d, 2H)8.28(s, 1H) 21

CH₃CO 78-801.30(s, 9H)2.21(s, 3H)2.31(s, 3H)7.07(dd, 2H)7.26(dd,1H)7.36(dd, 1H)7.53(d, 1H)7.57(dd, 2H)8.27(s, 1H) 22

CH₃CO 123-1262.24(s, 3H)7.38-7.81(m, 13H)8.35(s, 1H) 23

CH₃CO 113-1141.43(t, 3H)2.23(s, 3H)2.39(s, 3H)2.45(s, 3H)4.06(q,2H)6.78(s, 1H)7.80(s, 1H)8.73(s, 1H) 24

CH₃CO 390.89(t, 3H)1.29(m, 10H)1.80(tt, 2H)2.23(s, 3H)2.39(s, 3H)2.45(s,3H)3.97(t, 2H)6.75(s, 1H)7.81(s, 1H)8.71(s, 1H) 25

CH₂CO liquid2.18(s, 3H)3.92(s, 3H)6.92(d, 1H)7.29-7.37(m, 6H)7.70(dd,1H)8.16(s, 1H) 26

CH₃CO liquid2.19(s, 3H)6.92-7.52(m, 13H)8.20(s, 1H) 27

CH₃CO 75-762.23(s, 3H)2.53(s, 6H)7.17(d, 1H)7.50(dd, 1H)7.58(d,1H)8.30(s, 1H) 28

CH₃CO liquid2.00(s, 3H)3.93(s, 3H)6.18(dd, 1H)6.56(dd, 1H)6.81(d,1H)8.22(s, 1H) 29

CH₃CO 85-862.13(s, 3H)7.18(dd, 1H)7.58(d, 1H)7.80(d, 2H)8.84(s, 1H) 30

CH₃CO 133-1342.26(s, 3H)3.94(s, 3H)7.15(s, 1H)7.18(d, 1H)7.77(d,1H)7.78(d, 1H)7.93(d, 1H)7.97(s, 1H)8.46(s, 1H) 31

CH₃CO 119-1212.31(s, 3H)3.96(s, 3H)4.03(s, 3H)6.82(d, 1H)6.95(d,1H)7.41(t, 1H)7.87(dd, 1H)7.92(dd, 1H)9.46(s, 1H) 32

CH₃CO 1112.22(s, 3H)3.99(s, 3H)4.02(s, 3H)7.26(s, 1H)7.63(m, 2H)8.13(dd,1H)8.26(dd, 1H)8.83(s, 1H) 33

CH₃CO 1022.28(s, 3H)7.31-7.40(m, 6H)7.60(td, 1H)7.65(td, 1H)7.74(d,2H)8.45(dd, 1H)8.60(dd, 1H)8.93(s, 1H) 34

CH₃CO liquid2.20(s, 3H)3.86(s, 3H)7.02(d, 1H)7.35-7.53(m, 5H)7.69(s,1H)7.71(dd, 1H)8.33(s, 1H) 35

CH₃CO 112-1132.26(s, 3H)3.40(s, 3H)7.23(t, 1H)7.38-7.57(m, 6H)8.00(dd,1H)8.77(s, 1H) 36

CH₃CO 902.24(s, 3H)3.92(s, 3H)7.01(d, 1H)7.33(td, 1H)7.42(td,2H)7.57(dd, 2H)7.68(dd, 1H)8.19(d, 1H)8.82(s, 1H) 37

CH₃CO 129-1322.22(s, 3H)3.89(s, 3H)3.97(s, 3H)6.97(d, 2H)7.03(d,1H)7.79(d, 2H)7.94(dd, 1H)8.32(d, 1H)8.77(s, 1H) 38

CH₃CO liquid0.90(t, 3H)1.33(m, 8H)1.48(m, 2H)1.84(m, 2H)2.25(s,3H)4.05(t, 2H)6.99(d, 1H)7.32(td, 1H)7.41(t, 2H)7.57(dd, 2H)7.65(dd,1H)8.19(d, 1H)8.81(s, 1H) 39

CH₃CO 100-1022.22(s, 3H)7.00(d, 2H)7.12(m, 6H)7.32(t, 4H)7.54(d,2H)8.26(s, 1H) 40

CH₃CO 195-1962.27(s, 3H)7.54(dt, 1H)7.61(dd, 1H)7.65(d, 1H)7.68(dd,1H)8.24(dd, 1H)8.49(s, 1H)8.63(dd, 1H)8.70(d, 1H) 41

CH₃CO 122-1232.25(s, 3H)3.94(s, 2H)7.36(dt, 1H)7.41(dt, 1H)7.58(dd,1H)7.70(dd, 1H)7.82(d, 2H)8.00(s, 1H)8.42(s, 1H) 42

CH₃CO liquid0.93(t, 3H)0.95(t, 3H)1.41(m, 8H)1.79(m, 4H)2.22(s,3H)3.98(m, 4H)6.42(d, 1H)6.50(dd, 1H)7.90(d, 1H)8.67(s, 1H) 43

CH₃CO 140-1422.21(s, 3H)3.86(s, 3H)3.89(s, 3H)3.93(s, 3H)6.49(s,1H)7.43(s, 1H)8.71(s, 1H) 44

CH₃CO 830.88(t, 3H)1.20-1.36(m, 28H)1.44(m, 2H)1.60(m, 2H)2.96(t,2H)7.28(d, 2H)7.62(d, 2H)8.30(s, 1H) 45

CH₃CO 47-542.25(s, 3H)2.34(s, 3H)2.44(s, 3H)7.23(dd, 1H)7.32(d,1H)7.79(d, 1H)8.90(s, 1H) 46

CH₃CO 63-650.88(t, 3H)1.31(m, 8H)1.45(m, 2H)1.76(m, 2H)2.25(s,3H)4.33(t, 2H)6.97(dd, 1H)7.18-7.35(m, 2H)7.55(d, 2H)7.73(dd,1H)7.96(dd, 1H)8.37(s, 1H) 47

CH₃CO 106-1102.22(s, 3H)5.10(s, 2H)7.03(d, 2H)7.12(d, 2H)7.32-7.50(m,7H)7.55(d, 2H)8.27(s, 1H) 48

CH₃CO 119-1212.22(s, 3H)7.28(dd, 2H)7.46(dd, 1H)7.53(m, 2H)7.61(dd,2H)7.77-7.89(m, 3H)8.00(d, 1H)8.29(s, 1H) 49

CH₃CO 662.21(s, 3H)2.51(s, 3H)3.86(s, 3H)6.76(d, 1H)6.82(dd, 1H)7.89(d,1H)8.69(s, 1H) 50

CH₃CO 116-1172.24(s, 3H)7.24-7.30(m, 2H)7.46-7.53(m, 3H)7.60(dd,1H)7.85(d, 1H)8.30(s, 1H) 51

CH₃CO 72-740.90(gt, 3H)1.20-1.55(m, 10H)1.86(m, 2H)2.31(s, 3H)4.16(t,2H)7.25(d, 1H)7.40(dt, 1H)7.62(dt, 1H)7.77(dd, 1H)7.93(d, 1H)9.06(dd,1H)9.16(s, 1H) 52

CH₃CO liquid2.28(s, 3H)2.96(s, 6H)7.03(d, 1H)7.53(dt, 1H)7.61(dt,1H)7.79(d, 1H)8.24(dd, 1H)8.66(dd, 1H)8.87(s, 1H) 53

CH₃CO liquid1.44(t, 3H)2.25(s, 3H)4.36(q, 2H)7.28(dt, 1H)7.40(d,1HH)7.42(d, 1H)7.50(dt, 1H)7.84(dd, 1H)8.11(d, 1H)8.45(d, 1H)8.51(s, 1H)54

CH₃CO 144-1451.39(t, 3H)1.44(t, 3H)2.24(s, 3H)4.06(q, 2H)4.12(q,2H)6.93(dd, 2H)6.97(d, 1H)7.85(d, 2H)7.97(dd, 1H)8.44(d, 1H)8.69(s, 1H)55

CH₃CO 138-1392.26(s, 3H)7.51(t, 2H)7.60(d, 2H)7.63(t, 1H)7.82(d,2H)8.02(d, 2H)8.40(s, 1H) 56

CH₃CO 36-420.95(t, 3H)1.19(t, 6H)1.42(m, 4H)1.81(m, 2H)2.20(s,3H)3.39(q, 4H)3.97(t, 2H)6.06(d, 1H)6.26(dd, 1H)7.81(d, 1H)8.63(s, 1H)

TABLE 2

state/mp [° C.] Example M₁ R₁ x ¹H-NMR, δ [ppm] 57

CH₃CO 2 148-1502.22(s, 6H)6.82(d, 2H)7.22(t, 2H)7.44(t, 2H)8.12(d,2H)8.74(s, 2H) 58

CH₃CO 2 1651.47(t, 6H)2.25(s, 6H)4.13(d, 4HH)6.96(d, 2H)7.65(dd,2H)8.12(d, 2H)8.82(s, 2H) 59

CH₃CO 2 liquid2.16(s, 6H)2.26(t, 2H)3.86(s, 6H)4.26(t, 4H)7.02(dd,2H)7.09(t, 2H)7.59(dd, 2H)8.76(s, 2H) 60

CH₃CO 2 54-552.18(s, 6H)5.07(s, 4H)6.91(d, 4H)7.34(dd, 4H)7.40(m,6H)8.01(d, 2H)8.72(s, 2H) 61

CH₃CO 2 79-822.22(s, 6H)3.86(s, 6H)6.86(d, 2H)7.39(dd, 2H)7.99(d,2H)8.70(s, 2H) 62

CH₃CO 2 137-1402.24(s, 6H)7.39(d, 4H)7.69(d, 4H)8.36(s, 2H) 63

CH₃CO 2 150-1512.26(s, 6H)7.52(d, 4H)7.68(d, 4H)8.31(s, 2H)

TABLE 3

state/mp [° C.] ¹H-NMR, Example Ar₂ R₁ R₂ δ [ppm] 64

CH₃CO CH₃ 95-962.23(s, 3H)3.78(s, 6H)6.55(d, 2H)7.27(t, 1H) 65

CH₃CO CH₃ 81-822.25(s, 3H)2.33(s, 3H)3.78(s, 3H)3.79(s, 3H)6.86(d,1H)6.93(s, 1H)6.94(d, 1H) 66

CH₃CO CH₃ 77-792.29(s, 3H)2.48(s, 3H)4.03(s, 3H)6.80(d, 1H)7.45(d,1H)7.54(m, 2H)8.00(d, 1H)8.32(d, 1H) 67

phenyl-CO C₆H₁₃ liquid0.86(t, 3H)1.28-1.49(m,6H)1.73(tt, 2H)2.97(t,2H)4.06(s, 3H)6.86(d, 1H)7.53(m, 3H)7.65(m, 2H)8.12(dd, 2H)8.22(d,1H)8.33(d, 1H)9.04(d, 1H) 68

CH₃CO C₆H₁₃ liquid0.82(t, 3H)1.18-1.35(m, 8H)1.49(m, 2H)2.29(s,3H)2.91(t, 2H)7.167.64(m, 9H)7.98(m, 1H)8.43(m, 1H) 69

phenyl-CO C₅H₁₁ liquid0.82(t, 3H)1.28-1.48(m, 6H)1.70(t, 2H)2.96(t,2H)7.13(d, 1H)7.39-7.67(m, 10H)7.90(d, 1H)8.08(dd, 2H)8.39(d, 1H)8.80(d,1H)

EXAMPLE 70 Synthesis of 1-(4-Methoxynaphthyl)-octan-1,2-dione2-oxime-O-acetate

In formula III: Ar₂=4-Methoxynaphthoyl; R₁═COCH₃; R₂═C₆H₁₃

70.a 1-(4-Methoxynaphthyl)-octan-1,2-dione 2-oxime

10.0 g (35.2 mmol) of 1-(4-methoxynaphthyl)-octan-1-one are dissolved in35 mL of t-butyl methyl ether. HCl-gas is introduced into this solutionunder cooling in an ice bath, and methyl nitrite-gas, which is genaratedby adding H₂SO₄ aq. solution (3.5 mL of conc. H₂SO₄ and 7 mL of H₂O)into NaNO₂ (3.65 g, 52.7 mmol) in methanol (3 mL) and H₂O (3 mL), isintroduced for 10 min at an ice-bath temperature. Then, the reactionsolution is poured into ice, and the crude product is extracted witht-butyl methyl ether. This ether layer is washed with saturated NaHCO₃aq. solution and brine, dried over anhydrous MgSO₄, and then condensed.The residue is applied to column chromatography on silica gel with ethylacetate -hexane (10:90) as eluent. 2.02 g of yellow solid are obtained(18%). M.p. 92-93° C. ¹H-NMR spectrum (CDCl₃). δ [ppm]: 0.90 (t, 3H),1.31-1.55 (m, 6H), 1.59-1.65 (m , 2H), 2.79 (t, 2H), 4.06 (s, 3H), 6.80(d, 1H), 7.51 (t, 1H), 7.58 (t, 1H), 7.72 (d, 1H), 7.75 (d, 1H), 8.33(d, 1H), 8.44 (d, 1H).

70.b 1-(4-Methoxynaphthyl)-octan-1,2-dione 2-oxime-O-acetate

1.51 g (4.82 mmol) of 1-(4-Methoxynaphthyl)-octan-1,2-dione 2-oxime aredissolved in 15 ml of THF and the solution is cooled in an ice-bath.Acetyl chloride (0.49 g, 6.3 mmol) and triethylamine (0.73 g, 7.2 mmol)are added successively. The reaction solution is stirred at 0° C. for2.5 h and then poured into water. The THF layer is separated and washedwith saturated NaHCO₃ aq. solution and brine, followed by drying overMgSO₄. After condensation, the residue is applied to columnchromatography on silica gel with ethyl acetate-hexane (10:90) aseluent. 0.92 g of yellow oil are obtained (54%). mp: 68-71° C. ¹H-NMRspectrum (CDCl₃). δ [ppm]: 0.88 (t, 3H), 1.26-1.29 (m, 4H), 1.30-1.41(m, 2H), 1.58-1.63 (m , 2H), 2.24 (s, 3H), 2.84 (t, 2H), 4.08 (s, 3H),6.84 (d, 1H), 7.55 (t, 1H), 7.66 (t, 1H), 8.06 (d, 1H), 8.34 (d, 1H),8.96 (d, 1H).

In examples 71-72 the following sensitizers are used:

S-1 mixture of 2-isopropyl thioxanthone and 4-isopropylthioxanthone(^(RTM)OUANTACURE ITX)

S-2 4′-bis(diethylamino)-benzophenone (Michler's ketone)

EXAMPLE 71

A photocurable formulation, which serves as a model for a solder resistis prepared by mixing the following components:

-   -   47.30 parts by weight of a polyacrylate with 3-5% carboxyl        groups        -   (^(RTM)CARBOSET 525 provided by GF Goodrich)    -   37.64 parts by weight of trimetylolpropane triacrylate    -   4.30 parts by weight of polyvinylpyrrolidone (PVP 30)    -   10.76 parts by weight of hexamethoxymethylamine (^(RTM)CYMEL        301)    -   319.00 parts by weight methylenechloride    -   30.00 parts by weight methanol.

To that mixture either 0.5% (based on the solid content) of S-1, or 0.1%(based on the solid content) of S-2 and 2% (based on the solid content)of the initiator to be tested are added and stirred. All operations arecarried out under yellow light conditions. The sample to which initiatorhas been added is applied to an aluminum foil. The solvent is removed bydrying at 60° C. for 15 minutes in a convection oven. After drying thefilm thickness is 35-40 μm. A 76 μm thick polyester film is laminatedonto the dry film and a standardized tetst negative with 21 steps ofdifferent optical density (Stouffer wedge) is placed on top. The sampleis covered with a second UV-transparent film and pressed onto a metalplate by means of vacuum. Exposure is carried out in a first test seriesfor 2 seconds, in a second series for 5 seconds and in a third seiriesfor 10 seconds, using a metal halide lamp (SMX-3000, ORC). Followingexposure, the cover films and the mask are removed and the exposed filmis developed with 1.0% sodium carbonate aqueous solution for 3 minutesat 30° C. by using a spray type developer (Walter Lemmen, model T21).The sensitivity of the initiator system used is characterized byindicating the highest step number which remained (i.e. polymerized)after developing. The higher the number of steps, the more sensitive isthe tested system. The results are collected in table 4.

TABLE 4 Number of steps reproduced Photoinitiator after exposure time ofof example Sensitizer 2 sec. 5 sec. 10 sec. 1 S-1 7 12 14 1 S-2 6 10 123 S-1 7 11 13 3 S-2 6 10 12 4 S-1 7 11 13 5 S-1 6 10 12 7 S-1 7 11 13 9S-1 7 12 14 9 S-2 6 10 12 10 S-1 8 13 15 10 S-2 6 10 12 11 S-1 7 12 1413 S-1 7 12 14 14 S-1 8 13 15 15 S-1 8 13 15 15 S-2 6 10 12 16 S-1 7 1214 16 S-2 6 10 12 17 S-1 7 12 14 18 S-1 7 12 14 19 S-1 7 12 14 19 S-2 611 12 21 S-1 7 12 15 22 — 7 11 13 22 S-1 8 13 15 23 — 8 13 15 24 — 7 1215 24 S-1 8 13 15 25 S-1 7 12 15 26 S-1 7 11 14 27 — 7 11 13 27 S-1 8 1315 30 S-1 7 11 13 30 S-2 6 10 12 31 S-1 7 12 14 31 S-2 6 10 12 32 S-1 712 14 32 S-2 6 10 12 33 — 7 12 13 34 S-1 7 12 14 35 S-1 7 11 13 36 S-1 813 15 36 S-2 6 10 13 37 S-1 6 11 13 38 S-1 7 12 14 39 S-1 7 11 13 40 — 611 12 41 S-1 8 13 15 41 S-2 6 10 12 42 S-1 8 13 15 43 S-1 8 13 15 43 S-26 10 12 45 S-1 8 12 14 45 S-2 6 11 13 46 S-1 7 12 14 47 S-1 8 13 15 47S-2 6 11 13 48 — 6 11 13 48 S-1 8 13 15 48 S-2 7 12 14 49 S-1 9 13 15 49S-2 7 11 13 50 S-1 7 11 13 50 S-2 6 10 12 51 S-1 8 13 15 51 S-2 7 11 1352 — 6 10 11 52 S-1 6 10 12 52 S-2 6 10 12 57 S-1 6 10 12 58 — 6 11 1358 S-1 7 12 14 59 S-1 6 10 13 61 — 8 13 15 62 — 6 10 12 62 S-1 7 12 1470 — 6 11 13 70 S-1 7 12 14 70 S-2 7 11 13 66 S-1 8 13 15 66 S-2 7 11 1368 S-1 7 13 15 68 S-2 6 11 13

EXAMPLE 72 Preparation of poly(benzylmethacrylate-co-methacrylic acid)

24 g of benzylmethacrylate, 6 g of methacrylic acid and 0.525 g ofazobisisobutyronitrile (AIBN) are dissolved in 90 ml of propylene glycol1-monomethyl ether 2-acetate (PGMEA). The resulting reaction mixture isplaced in a preheated oil bath at 80° C. After stirring for 5 hours at80° C. under nitrogen, the resulting viscous solution is cooled to roomtemperature and used without further purification. The solid content isabout 25%.

A photocurable composition for a sensitivity test is prepared by mixingthe following components:

-   -   200.0 parts by weight of copolymer of benzylmethacrylate and        methacrylic acid (benzylmethacrylate: methacrylic acid=80: 20 by        weight) 25% propylene glycol 1-monomethyl ether 2-acetate        (PGMEA) solution, prepared as described above,    -   50.0 parts by weight of dipentaerythritol hexaacrylate ((DPHA),        provided by UCB Chemicals),    -   4.5 parts by weight of the photoinitiator,    -   1.8 parts by weight of the sensitizer, and

150.0 parts by weight of propylene glycol 1-monomethyl ether 2-acetate(PGMEA).

All operations are carried out under yellow light. The compositions areapplied to an aluminum plate using an electric applicator with a wirewound bar. The solvent is removed by heating at 100° C. for 2 minutes ina convection oven. The thickness of the dry film is approximately 2 μm.A standardized test negative film with 21 steps of different opticaldensity (Stouffer step wedge) is placed with an air gap of around 100 μmbetween the film and the resist. Exposure is carried out using a 250 Wsuper high pressure mercury lamp (USHIO, USH-250BY) at a distance of 15cm. A total exposure dose measured by an optical power meter(ORC UVLight Measure Model UV-M02 with UV-35 detector) on the test negativefilm is 500 mJ/cm². After exposure, the exposed film is developed with1% sodium carbonate aqueous solution for 100 sec. at 30° C. by using aspray type developer (Walter Lemmen, model T21). The sensitivity of theinitiator system used is characterized by indicating the highest numberof the step remained (i.e. polymerized) after developing. The higher thenumber of steps, the more sensitive is the system tested. The resultsare listed in table 5.

TABLE 5 Photoinitiator Number of steps reproduced of example Sensitizerafter exposure of 500 mJ/cm² 1 — 10 1 S-1 12 1 S-2 13 3 S-1 11 3 S-2 127 S-1 10 7 S-2 11 9 — 11 9 S-1 13 9 S-2 12 11 S-1 12 11 S-2 12 13 S-1 1113 S-2 12 14 S-1 10 14 S-2 10 15 S-1 11 15 S-2 12 16 S-1 11 16 S-2 12 17S-1 12 17 S-2 13 18 S-1 13 18 S-2 12 19 S-1 12 19 S-2 13 21 — 11 21 S-113 21 S-2 12 22 — 15 23 — 12 24 — 12 24 S-1 13 25 S-1 12 25 S-2 13 26 —11 26 S-1 12 26 S-2 13 27 — 14 27 S-1 15 27 S-2 15 29 S-2 10 30 S-1 1230 S-2 13 31 S-1 14 31 S-2 13 32 — 11 32 S-1 12 32 S-2 12 33 — 13 34 S-113 34 S-2 13 35 S-1 11 35 S-2 11 36 — 10 36 S-1 13 36 S-2 13 37 — 10 37S-1 12 37 S-2 12 38 S-1 12 38 S-2 11 39 S-1 13 39 S-2 13 40 — 13 40 S-114 41 S-1 13 41 S-2 14 42 S-1 11 42 S-2 11 43 S-1 13 43 S-2 13 45 — 1045 S-1 12 45 S-2 11 46 — 11 46 S-1 12 46 S-2 12 47 — 12 47 S-1 13 47 S-213 48 — 14 48 S-1 15 49 S-1 14 49 S-2 13 50 — 12 50 S-1 13 51 S-1 13 51S-2 12 53 S-1 14 53 S-2 13 54 — 10 55 S-1 12 55 S-2 11 57 S-2 11 58 — 1158 S-1 12 58 S-2 13 59 S-2 11 60 — 13 61 — 13 62 — 12 62 S-1 14 62 S-213 70 — 13 70 S-1 14 67 — 11 67 S-1 12 66 S-1 12 66 S-2 13 68 — 12 68S-1 14 68 S-2 13

1. Compounds of the formulae I and II

wherein R₁ is C₄-C₉cycloalkanoyl, or C₁-C₁₂alkanoyl which isunsubstituted or substituted by one or more halogen, phenyl or CN; or R₁is C₄-C₆alkenoyl, provided that the double bond is not conjugated withthe carbonyl group; or R₁ is benzoyl which is unsubstituted orsubstituted by one or more C₁-C₆alkyl, halogen, CN, OR₃, SR₄ or NR₅R₆;or R₁ is C₂-C₆alkoxycarbonyl, benzyloxycarbonyl; or phenoxycarbonylwhich is unsubstituted or substituted by one or more C₁-C₆alkyl orhalogen; Ar₁ is

both optionally substituted 1 to 4 times by halogen, C₁-C₁₂alkyl,C₃-C₈cycloalkyl, benzyl, OR₃, SR₄ or NR₅R₆, wherein the substituentsOR₃, SR₄ or NR₅R₆ optionally form 5- or 6-membered rings via theradicals R₃, R₄, R₅ and/or R₆ with further substituents on the phenylring or with one of the carbon atoms of the phenyl ring or with thesubstituent R₈; x is 2 or 3; M₁ when x is 2, is

each of which optionally is substituted 1 to 8 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl; phenyl which is unsubstituted orsubstituted by one or more OR₃, SR₄ or NR₅R₆; or each of which issubstituted by benzyl, benzoyl, C₂-C₁₂alkanoyl; C₂-C₁₂alkoxycarbonyloptionally interrupted by one or more —O— and/or optionally substitutedby one or more hydroxyl groups; or each of which is substituted byphenoxycarbonyl, OR₃, SR₄, SOR₄, SO₂R₄ or NR₅R₆; provided that (xix) M₁is not 1,3-phenylene, 1,4-phenylene, 1-acetoxy-2-methoxy-4,6-phenyleneor 1-methoxy-2-hydroxy-3,5-phenylene; M₁, when x is 3, is

each of which optionally is substituted 1 to 12 times by halogen,C₁-C₁₂alkyl, C₃-C₈cycloalkyl; phenyl which is unsubstituted orsubstituted by one or more OR₃, SR₄ or NR₅R₆; or each of which issubstituted by benzyl, benzoyl, C₂-C₁₂alkanoyl; C₂-C₁₂alkoxycarbonyloptionally interrupted by one or more —O— and/or optionally substitutedby one or more hydroxyl groups; or each of which is substituted byphenoxycarbonyl, OR₃, SR₄, SOR₄, SO₂R₄ or NR₅R₆; n is 1-20; M₄ is adirect bond, —O—, —S—, —SS—, —NR₃—, —(CO)—, C₁-C₁₂alkylene,cyclohexylene, phenylene, naphthylene, C₂-C₁₂alkylenedioxy,C₂-C₁₂alkylenedisulfanyl, —(CO)O—(C₂-C₁₂alkylene)—O(CO)—,—(CO)O—(CH₂CH₂O)_(n)—(CO)— or —(CO)—(C₂-C₁₂-alkylene)—(CO)—; or M₄ isC₄-C₁₂alkylene or C₄-C₁₂alkylenedioxy, each of which is optionallyinterrupted by 1 to 5 —O—, —S— and/or —NR₃—; M₅ is a direct bond, —CH₂—,—O—, —S—, —SS—, —NR₃— or —(CO)—; M₆ is

R₃ is hydrogen or C₁-C₂₀alkyl; or R₃ is C₂-C₈alkyl which is substitutedby —OH, —SH, —CH, C₃-C₆alkenoxy, —OCH₂CH₂CN, —OCH₂CH₂(CO)O(C₁-C₄alkyl),—O(CO)-C₁-C₄alkyl, —O(CO)-phenyl, —(CO)OH or —(CO)O(C₁-C₄alkyl); or R₃is C₂-C₁₂alkyl which is interrupted by one or more —O—; or R₃ is—(CH₂CH₂O)_(n+1)H, —(CH₂CH₂O)_(n)(CO)—C₁-C₈alkanoyl, C₃-C₁₂alkenyl,C₃-C₆alkenoyl, C₃-C₈cycloalkyl; or R₃ is benzoyl which is unsubstitutedor substituted by one or more C₁-C₆alkyl, halogen, —OH or C₁-C₄alkoxy;or R₃ is phenyl or naphthyl each of which is unsubstituted orsubstituted by halogen —OH, C₁-C₁₂alkyl, C₁-C₁₂alkoxy, or —(CO)R₇; or R₃is phenyl-C₁-C₃alkyl, or Si(C₁-C₆alkyl)_(r)(phenyl)_(3−r); r is 0, 1, 2or 3; R₄ is hydrogen, C₁-C₂₀alkyl, C₃-C₁₂alkenyl, C₃-C₈cycloalkyl,phenyl-C₁-C₃alkyl; C₂-C₈alkyl which is substituted by —OH, —SH, —CN,C₃-C₆alkenoxy, —OCH₂CH₂CN, —OCH₂CH₂(CO)O(C₁-C₄alkyl), —O(CO)-C₁-C₄alkyl,—O(CO)-phenyl, —CO)OH or —(CO)O(C₁-C₄alkyl); or R₄ is C₂-C₁₂alkyl whichis interrupted by one or more —O— or —S—; or R₄ is —(CH₂CH₂O)_(n+1)H,—(CH₂CH₂O)_(n)(CO)-C₁-C₈alkyl, C₂-C₈alkanoyl, benzoyl, C₃-C₁₂alkenyl,C₃-C₆-alkenoyl; or R₄ is phenyl or naphthyl, each of which isunsubstituted or substituted by halogen, C₁-C₁₂alkyl, C₁-C₁₂alkoxy,phenyl-C₁-C₃alkyloxy, phenoxy, C₁-C₁₂alkylsulfanyl, phenylsulfanyl,—N(C₁-C₁₂alkyl)₂, diphenylamino, —(CO)R₇, —(CO)OR₇ or (CO)N(R₇)₂; R₅ andR₆ independently of each other are hydrogen, C₁-C₂₀alkyl,C₂-C₄hydroxyalkyl, C₂-C₁₀-alkoxyalkyl, C₃-C₅alkenyl, C₃-C₈cycloalkyl,phenyl-C₁-C₃alkyl, C₂-C₈alkanoyl, C₃-C₁₂alkenoyl, benzoyl; or R₅ and R₆are phenyl or naphthyl each of which is unsubstituted or substituted byC₁-C₁₂alkyl, C₁-C₁₂alkoxy or —(CO)R₇; or R₅ and R₆ together areC₂-C₆alkylene optionally interrupted by —O— or —NR₃— and/or optionallysubstituted by hydroxyl, C₁-C₄alkoxy, C₂-C₄alkanoyloxy or benzoyloxy;and R₇ is hydrogen, C₁-C₂₀alkyl; C₂-C₈alkyl which is substituted byhalogen, phenyl, —OH, —SH, —CN, C₃-C₆alkenoxy, —OCH₂CH₂CN,—OCH₂CH₂(CO)O(C₁-C₄alkyl), —O(CO)-C₁-C₄alkyl, —O(CO)-phenyl, —(CO)OH or—(CO)O(C₁-C₄alkyl); or R₇ is C₂-C₁₂alkyl which is interrupted by one ormore —O—; or R₇ is —(CH₂CH₂O)_(n+1)H, —(CH₂CH₂O)_(n)(CO)-C₁-C₈alkyl,C₃-C₁₂alkenyl, C₃-C₈cycloalkyl; or is phenyl optionally substituted byone or more halogen, —OH, C₁-C₁₂alkyl, C₁-C₁₂alkoxy, phenoxy,C₁-C₁₂alkylsulfanyl, phenylsulfanyl, —N(C₁-C₁₂alkyl)₂ or diphenylamino;R₈ is C₁-C₁₂alkyl optionally substituted by one or more halogen, phenyl,CN, —OH, —SH, C₁-C₄-alkoxy, —(CO)OH or —(CO)O(C₁-C₄alkyl); or R₈ isC₃-C₆alkenyl; or phenyl optionally substituted by one or moreC₁-C₆alkyl, halogen, CN, OR₃, SR₄ or NR₅R₆.
 2. Compounds of the formulaII according to claim 1, wherein R₁ is C₂-C₆alkoxycarbonyl orbenzyloxycarbonyl; C₁-C₁₂alkanoyl which is unsubstituted or substitutedby one or more halogen or phenyl; or R¹ is C₄-C₆alkenoyl, provided thatthe double bond is not conjugated with the carbonyl group; or R¹ isbenzoyl which is unsubstituted or substituted by one or more C₁-C₆alkylor halogen; M₁ is

each of which optionally is substituted 1 to 8 times by halogen,C₁-C₁₂alkyl, phenyl, OR₃, SR₄ or NR₅R₆.
 3. Compounds of the formula IIaccording to claim 1, wherein R¹ is C₁-C₁₂alkanoyl, benzoyl orC₂-C₆alkoxycarbonyl; x is 2; M₁ is

which optionally is substituted by OR₃; M₄ is a direct bond, —O—, —S—,—SS—, or C₂-C₁₂alkylenedioxy; R₃ is C₁-C₈alkyl, phenyl orphenyl-C₁-C₃alkyl; R₃′ is C₁-C₈alkyl, C₃-C₁₂alkenyl orphenyl-C₁-C₃alkyl; R₄ is C₁-C₂₀alkyl, phenyl-C₁-C₃alkyl, benzoyl; or isphenyl or naphthyl, both of which are unsubstituted or substituted byC₁-C₁₂alkyl, phenyl-C₁-C₃alkyloxy, —(CO)R₇ or —(CO)OR₇; R₅ and R₆independently of each other are hydrogen, phenyl-C₁-C₃alkyl,C₂-C₈alkanoyl, or phenyl; R₇ is C₁-C₂₀alkyl or phenyl; R₈ is phenyloptionally substituted by OR₃.
 4. Compounds of the formula I accordingto claim 1, wherein R₁ is C₄-C₉cycloalkanoyl, or C₁-C₁₂alkanoyl which isunsubstituted or substituted by one or more halogen, phenyl or CN; or R₁is C₄-C₆alkenoyl, provided that the double bond is not conjugated withthe carbonyl group; or R₁ is benzoyl which is unsubstituted orsubstituted by one or more C₁-C₆alkyl, halogen, CN, OR₃, SR₄ or NR₅R₈;Ar₁ is

both optionally substituted 1 to 4 times by halogen, C₁-C₁₂alkyl,C₃-C₈cycloalkyl or benzyl.
 5. Compounds of the formula I according toclaim 4, wherein R₁ is C₄-C₉cycloalkanoyl, or C₁-C₁₂alkanoyl which isunsubstituted or substituted by one or more halogen, phenyl or CN; andAr₁ is